Silkworm

In this preparation for moving, paper has the advantage over the netting; it is stiffer and does not lump the worms together in the middle. They may now be spread upon the shelves or trays, care being taken to give them plenty of space, as they grow rapidly. Each day's hatching should be kept separate in order that the worms may be of a uniform size, .and go through their different moltings or sick nesses with regularity and uniformity; and all eggs not hatched after the fourth day from the appearance of the first should be thrown away, as they will be found to contain inferior, weakly, or sickly worms. It is calculated that one ounce of eggs of a good race will produce 100 pounds of fresh cocoons; while for every additional ounce the percentage is reduced if the worms are all raised together, until for twenty ounces the average does not exceed twenty-five pounds of cocoons per ounce. Such is the general ence throughout France, according to GuErin M. neville, and it shows the importance of ing them in small broods, or of rearing on a moderate scale. The young worms may be removed from place to place by means of a small camel's-hair brush, but should be handled as little as possible. The best naode of feeding and caring for them is by continuing the use of the net first mentioned As the worms increase in size the net must have larger meshes, and if it should be used every time fresh food is furnished, it will save a large amount of time and care. It entirely obviates the necessity of handling the worms, and ables the person having charge of them to keep them thoroughly clean; for, while they pass up through the net to take their fresh food, their excrement drops through it and is always taken up with the old litter beneath. It also acts as a detective of ease; for such worms as are jured, feeble, or sickly, usually fail to mount through the meshes and should he carried off and destroyed with the refuse in the old net below. Placing on of the new net and carrying away of the old is such a great venience and time-saver that, in France, for many years, paper, stamped by machinery with holes of different sizes, suited to the different stages of the worms, has been used. The paper has the advantage of cheapness and stiffness, but a discussion as to the best material is sary here, the aim being to enforce the principle of the progressive rise of the worms. Details will suggest themselves to the operator. Where the nets are not used, there is an advantage in feeding the worms upon leaf-covered twigs and branches, because these last allow a free passage of air, and the leaves keep fresh a longer time than when plucked. In thus feeding with branches consists the whole secret of the Califor nia system, so much praised and advocated by M. L. Prevost. The proper, stamped paper not being easily obtained in this country, mosquito netting will be found a very fair substitute while the worms are young, and when they are larger I have found thin slats of some non-resinous and well-seasoned wood, tacked in parallel lines to a frame just large enough to set in the trays, very serviceable and convenicnt—small square blocks of similar wood being used at the corners of the tray to support tbe frame while the worms are passing up through it. Coarse twine-netting stretched over a similar frame will answer the same purpose, but wire-netting is less useful, as the worms dislike the smooth metal. Where branches, and not leaves, are fed, the Osage Orange has the advantage of Mulberry, ns its spines prevent too close settling or packing, and thus insure ventilation. It is recommended by many to feed the worms while in their first age, and, consequently, weak and tender, leaves that have been cut up or hashed, in order to give them more edges to eat upon and make less work for them. This, however, is hardly necessary with Annuals, although it is quite generally practiced in France. With the second brood. of Bivoltins it might be advisable, inasmuch as the leaves at the season of the vear when they appear, have attained their full growth and are a little tough for the newly-hatched individuals. In the spring, however, the leave-. are small and tender, and nature has provided the young worms with sufficiently strong jaws to cut them. Many rules have been laid down as to regularity of feeding, and much stress has been put upon it by some writers, most advising four meals a day at regular intervals, while it given number of meals between rnolts has also been urged; but such definite rules are of but little avail, as so much depends upon circumstances and condi tions. The food should, in fact, be renewed whenever the. leaves have been devoured, or whenever they have become in the least dry, which, of course, takes place rnuch quicker when young and tender than when mature. This also is an objection to the use of the hashed leaves, as, of course, they would dry very quickly. The worms eat most freely early in the morning and late at night, and it would be well to renew the leaves abundantly between 5 and 6 a. m. and between 10 and 11 p. m. One or two additional meals should be given during the day, according as the worms may seem to need them Great care should be taken to pick the leaves for the early morning meal the evening before, as when picked and fed with the dew upon them they are more apt to induce disease. Indeed, the rule should be laid down, never feed wet or damp leaves to your worms. In case they are picked during a rain, they should be thoroughly dried before being fed; and on the approach of a storm, it is always well to lay in a stock, which should be kept from heatin,,o. by occasional stir ring. Care should also be taken to spread the leaves evenly, so that all may feed alike. Dur ing this first and most delicate age the worm requires much care and watching. As the fifth or sixth day approaches, signs of the first inolt begin to be noticed. The worm begins to lose appetite and grow more shiny, and soon the dark spot already described appears above the head. Feeding should now cease, and the shelves or trays should he made as clean as possible. Some will undoubtedly undergo the shedding of the skin much more easily and quickly Clan others, but no feed should be given to these forward individuals until nearly all have completed the molt. This serves to keep the batch together, and the first ones will wait one or even two days without injury from want of food. It is, how ever, unnecessary to wait for all, as there will always be some few which remain sick after the great majority have cast their skins. These should either be set aside and kept separate, or destroyed, as they are usually the most feeble and most Inclined to disease; otherwise, the batch will grow more and more irregular in their molt ings and the diseased worms will assuredly contaminate the healthy ones. It is really doubt ful whether the silk raised from these weak indi viduals will pay for the trouble of rearing them separately, and it will be better perhaps to des troy them. The importance of keeping each batch together, and of causing the worms to molt simultaneously, can not be too much insisted upon as a means of saving time. As soon as the great majority have molted they should be copi ously fed, and, as they grow very rapidly after each molt, and as they must always he allowed plenty of room, it will probably become neces sary to divide the batch, and this is readily done at any meal by removing the net when about half of the worms have risen and replacing it by an additional one. The space allotted to each batch should, of course, be increased proportion ately with the growth of the worms. The same precautions should be observed in the three suc ceeding molts as in this first one. As regards the temperature of the rearing-room, great care should be taken to avoid all sudden changes from warm to cold, or rice versa. A mean temperature of 75° or 80° F. will usually bring the worms to the spinning-point in the course of thirty-five days after hatching, but the rapidity of development depends upon a variety of other causes, such a,s quality of leaf, race of worm, etc. If it can be prevented, the temperature should not be per mitted to rise very much above 80°, and it is for this reason that a room with a northern or north eastern exposure was recommended as preferable to any other. The air should be kept pure all of the time, and arrangements should be made to secure a good circulation. Great care should be taken to guard against the incursions of ants and other predaceous insects, which would make sad havoc among the worms were they allowed an entrance, and all through the existence of the insect, from the egg to the moth, rats and mice are on the watch for a chance to get at them, and are to be feared ahnost its much as any other enemy the Silkworm has. The second and third casting of the skin takes place with but little more difficulty than the first, but the fourth is more laborious, and the worms not only take more time in undergoing it, but more often perish in the act. At this molt it is perhaps better to give the more forward individuals a light feed as soon as they have completed the change, inasmuch as it is the last molt and but little is to be gained by the retardation, whereas it is important to feed them all that they will eat, since much of the nutri ment given during the last age goes for the elab oration of the silk. At each successive molt the color of the worm has been gradually hitening, until it is now of a decided cream color. Some breeds, however, remain dark, and occasionally there is an individual with zebra-like markings. During these last few days the worms require the greatest care and attention. All excrement and litter must be often removed, and the sickly and diseased ones watched for and removed from the rest. The quantity of leaves which they devour in this fifth age is something enormous, and the feeding will keep the attendant busily employed. Slimmed up, the requisites to successful Silk. worm raising are: 1. Uniformity of age in the individuals of the same tray, so as to insure their molting simultaneously. 2. No intermission in the supply of fresh food, except during the molt ing periods. 3. Plenty of room, so that the worms may not too closely crowd each other. 4. Fresh air and as uniform temperature as pos .sible. 5. Cleanliness. The last three are par ticularly necessary during the fourth and fifth ages. While small, the frass, dung, and detritus .dry rapidly, and may, though they should not, be left for several days in a. tray with impunity, but lie who allows his trays to go uncleaned for more than a du during the ages mentioned will suffer in the disease and mortality of his worms just as they are reaching the spinning-point. With eight or ten days of busy feeding, after the last molt, the worms, as we have learned before, will begin to lose appetite, shrink in size, become restless, and throw out silk,and the arches for the spinning of the cocoons must now be prepared. These can be made of twigs of different trees, two or three feet long, set up upon the shelves over the worms, and made to interlock in the form of an arch above them. Interlace these twigs with broom-corn, hemlock, or other well dried brush. The feet of each arch should be only about a foot apart. The temperature of the room should now he kept about 80°, as the silk does not flow so freely in a cool atmosphere. The worms will immediately mount into the branches and commence to spin their cocoons. They will not all, however, mount at the same time, and those which are more tardy should be fed often, but in small quantities at a time, in order to economize the leaves, as almost every moment some few will quit and mount. There will always be a few which altogether fail to mount, and prefer to spin in their trays. It is best, therefore, after the bulk have mounted, to remove the trays and lay brush carefully over them. The fact that the worms already

mounted make a final discharge of soft and semi fluid excrement before beginning to spin makes this separation necessary, as otherwise the cocoons of the lower ones would be badly soiled. As the worms begin to spin they should be care fully watched, to guard against two or three of them making what is called a double or treble cocoon, which would be unfit for reeling pur poses. Whenever one worm is about to spin up too near another, it should be carefully removed to another part of the arch. In two or three days the spinning will have been completed, and in six or seven the chrysalis will be formed. Eight days from the time the spinning commenced, it will be time to gather the cocoons. The arches should be carefully taken apart, and the spotted or stained cocoons first removed and laid aside. Care should be taken not to stain the clean ones with the black fluids of such worms as may have died and become putrid, for there are always a few of these in every cocoonery. The outer cocoons of loose or floss silk are then torn from the inner cocoons or pods, and the latter separ ated according to color, weight, and firmness of texture; those which best resist pressure indicat ing that the worm has best accomplished its -work. Too much care can not be taken to remove the soft or imperfect cocoons, as, if mixed with the firm ones, they would be surely crushed and soil the others with their contents. The very best of the firm cocoons are now to be chosen as seed for the next year, unless the raiser prefers buying his eggs to the trouble of caring for the moths and keeping the eggs through the winter. Eggs bought from large establishments are, however apt to be untrustworthy, and it is well for all silk-raisers to provide their own seed. These cocoons should be chosen for their firmness, and the fineness and color of the silk, rather than for their size. Mr. Crozier says If white, take them of the purest white, neither soft nor satin-like ; if yellow, give preference to the straw-colored, which are the most sought after; and, last, if they are the green of Japan, the greener they are, of a dark, sharp color, very glossy, the better is the quality of the thread. Discard the pale shades in the last breed. If there are any double or treble cocoons in the batch, of the right color, quality, and con sistency, they should be used before the others, as they are just as good for breeding purposes, though unfit for reeling. In estimating the quantity that will be required, the following figures will be of use: The general estimate is always made of 40,000 eggs to the ounce, and also that each female lays from 300 to 400 eggs. Taking the higher estimate, it will require only 100 females to lay an ounce of eggs; taking the lower, it will require 133. It will, therefore, not be safe to take fewer than 200 cocoons, half males and half females, if an ounce of seed is desired, and from that to 225 would be safer. While it may not always be possible to deter mine the sex of the cocoons by their shape, we may approximately separate them by weighing. The whole quantity set aside for breeding pur poses is first weighed in order to get the aver age, and then each one is weighed separately, and all above the average may be pretty accu rately considered females and all below it males, These breeding cocoons should now be either pasted upon card-board on their sides, or strung upon a string, great care being taken to run the needle through the silk only and not deep enough. to injure the chrysalis, the object being in both cases to secure the cocoon so that the moth can the more readily make its escape. They can be laid aside in a rat-proof place to await tbe appear ance of the moths, and in the mean time the other cocoons should be taken care of. In most silk producing countries the parties who raise the cocoons sell them to the reeling establishments before suffocation is necessary, as these estab lishments have better facilities for this work than are to be found in private families. If, how ever, the reeling is done by- the raiser, or some time must elapse before the cocoons can be sent to a reeling establishment, some means must be used to kill the contained chrysalis before the cocoon is injured for reeling psurposes by tbe egress of the moth. This can be done by stifling them with steam or choking them by dry heat. Steaming is the surest, quickest, and best method, if the facilities are at hand. It can be done at any steam mill. The cocoons are laid upon shelves in a tightly-sealed box and the steam is turned in. Twenty minutes will suffice to do the required work, and the cocoons are then dried in the sun. The dry heat method occupies a much longer time. The cocoons are placed in shallow baskets and slipped on iron drawers into au oven which is kept heated to a tempera ture of about 200° Fahr. This should not be increased for fear of burning the silk. This ope ration lasts from two to twenty-four hours. A certain humming noise continues so long as there is any lite, and its cessation is an indica tion that the cluTsalids are all dead. Where the choking is well done there is little loss, only about one per cent, of the cocoons bursting at the ends. After choking in this marmer, the cocoons should be strewn upon long, wooden shelves in the shade, with plenty of air, and. for the first few days, frequently stirred. After remaining on these shelves for about two months, with occasional stirrings, the chrysalids become quite dry and the cocoons will pre serve indefinitely. They are, however, still sub ject to the attacks of rats and mice, and the lit tle beetles known as museum pests, belonging to the genera Dsrmestes and Anthrenus, are attracted by the dead chrysalis within and will penetrate the cocoon, injuring it for reeling pur poses. In the warm, Southern States the dry heat choking can be accomplished by simple exposure to the sun. This was done by 3l. L. Prevost, in Southern California, and is practiced habitually by 3Ir. Crozier in Silkville, Kansas, who says: Here the cocoons need only to be fully exposed to the rays of the sun, from nine o'clock in the morning till four o'clock in tbe afternoon. Two or three days of such exposure are sufficient. But, as some time strong wind can annihilate the effect of the sun's warmth, it is good to have for that purpose long boxes, four feet wide, side,s six inches high, to be cov ered with glass frames. This will increase the heat, and, by absorbing the air of the box, stifle your chrysalis most surely. Ed. Muller, another California grower, (Nevada county), always makes use of this method of stiffing by the sun's rays. but says that the glass cover of the box should be left cracked open to allow the evapo ration of the moisture, which otherwise would collect in large drops upon the glass, and, falling back upon the cocoons, would keep them moist for a longer time. Do not, however, allow the ants to creep in at the crack, as they too will penetrate the cocoon to feed upon the chrysalis. In the colder climate,s it has been suggested that the chrysalis could be well choked, with no injury to the cocoons, by placing then) in a vacuum box and exhausting, the air. Chloro form has been used to a certain extent, and experiments are now being made in France with sulph-hydric acid gas, a vapor which is evolved from the mixture of dilute sulphuric acid and sulphide of iron; also with bisulphide of carbon. In from to twelve to twenty days from the time when the worm commenced to spin, the moths will begin to issue from the cocoons laid aside for breeding purposes. They issue abundantly dur ing the early rnorning hours, from four to eight o'clock, and as they appear, they should be taken by the wings and the sexes kept apart for a short time. The males may be readily distin guished from the females by their broader antennte and smaller bodies, as also by the inces sant fluttering of their wings. The females remain comparatively quiet, their abdomens being heavy and distended with eggs. A. few hours after issuing, the sexes, in equal numbers, may be placed together, great care being taken to destroy any that are at all deformed, in order to keep the breed as fine a.s possible. They should be placed upon paper or card-board, and the room should be kept as dark as possible in order that the males shall not uncouple them selves.. For the complete impregnation of the eggs, the sexes should be kept together six hours. neither more nor less, and occasionally visited in order to replace those males which may have become separated. Should there, on this day. more males than females is.sue, the super fluous males may be put in a closed box and kept till the next day. when the state of things may be reversed. Should there, on the other hand, be a superfluity of females, a sufficient number of the strongest and most vigorou, males should be uncoupled at four hours and placed with the unpaired females for six hours more. AS the pairs are uncoupled at the end of six hours, care should be taken to injure neither sex. The female should be held by the wings with one hand and the abdomen of the male gently pre,ssed with the other. The males may then be laid aside in a box, as there may be use for them before all the moths have appeared. After all the females are impregnated, however, they rnay be thrown away. These last, as soon as separated, should be placed for a few minutes upon sheets of blotting-paper, where they will free themscives of a quantity of greenish-yellow fluid. From the blotting-paper they should be transferred to trays lined with cloth upon which the eggs are to be laid. This cloth should be of the smoothest sort of woolen stuff rather than of linen or paper. if it is desired to remove the eggs at a future time, as they will stick so fast to the latter that it will be difficult to remove without bruising them. Upon these trays they may be placed in rows, and will immediately commence depositing. It is advisable to tip up the trays at one end so that they incline a little, as the moths are then more apt to lay their eggs uniformly. They should also be kept in the dark, in accord ance with the nocturnal habit of the moth. The temperature of the room should be kept at about 75', and plenty of air given during oviposition. All of- the thoroughly impregnated eggs will be laid in about twenty-four hours, and the moth should be removed after that length of time. She may continue depositing a short time longer, but the eggs should be kept by themselves and not rnixed with the others. It will be well, also, if the best and purest breed be desired, to keep the eggs of those moths which were coupled with males that had been used before, separated from the eggs laid by those which were coupled with virgin males. The eggs are best preserved on the cloth where originally deposited, as they are protected by a natural coating of varnish, and, being fastened, the worms, when hatching, eat their way out better. For commercial purposes, however. they are usually detached during the winter by immersing the cloth containing them in cool,soft water for a few moments; the moist ure being then drained off by means of blot ting paper, and the eggs gently removed with a paper-knife. They are then washed in soft water, thoroughly dried, and put away for keep ing. All eggs which swim ou the surface are considered bad and discarded. The Japanese producers sell their eggs on cards or cartoons made of coarse silk. The cards are placed in wooden frames, the rims of which are varnished, so that the moths—disliking the varnish—are made to confine their eggs upon the cards, which are consequently covered in a yery regular and uniform manner. The egg retains the character istic color of the unimpregnated ones--light yellow—for twelve or fifteen days, when it gradually acquires the gray, lavender, or ish tint of impregnation. The moths live but a few da,ys after having perpetuated their kind.