Fig. 5 exhibits a section of a potato; g, the root stem; a a, sections of eyes; t t t exhibits the posi tion of other eyes, but not in section. It will be seen that the inner markings exhibit a series of central circular and radiating lines leading from and returning to the root-branch g. These lines represent the arrangement of the vascular bun dles of the potato. When a potato is cut in two, sectionally, lines will be exhibited as shown, and, if exposed to the action of the air for a short time, the nitrogenous matter in the immediate vicinity of the vascular bundles blackens. The starch is inclosed in three cella. They consist of, first, an outer cellulose transparent cell; secondly, an opaque nitrogenous cell or lining; and thirdly, an inner cell, composed of very transparent cellulose, in which the starch-granules grow; b represents such a cell. These cells contain from thirty to sev enty granules. c represents a broken cell, from which the starch is seen as if in the act of leaving; a represents a portion of a broken cell; p, precipi tated starch. The starch-granules, individually considered, consist of starch and cellulose, the starch proper and a cellulose covering or cell. A reference to Fig. 6, F, will show the position of cellulose cells a, d, t. They are held in position in the potato by the nitrogenous cell t, which is held in turn by an outer and inner cellulose cell, a, d. When a sound potato is grated down, all these cells are broken, because of their per fect cohesion to one another. One cell can not be broken without breaking all. But in the case of rotting potatoes, the nitrogenous cell which binds the three together is partly removed by the fungoid action, but principally by infuso rial life (bacterio) which live on it. The inner or center cell containing the starch is thereby lib erated. This is owing partly .to the soft and
character of the cells and the machinery used in reducing the potatoes to a pulp, and being so buoyant as to float the starch granules within them, are carried away in the process of washing. Fig. 7 shows the fungus (Botrytis eiticola) of a mature grape leaf. This fungus at tacks the summer or second growth leaves and produces either by absorption of the sap, or by cellular disorganization caused by its processes. It is of a whitish spotted appearance when at tacked, and causes the withering of the leaves attacked. A dry atmosphere is the preventive to the attack, the first appearance of this fungus being observed on the under side of the leaf. Fig. 8 shows fungus of the germs uncinula, a fungus found on the upper surface of the native grape vines in autumn. No. 1, 2, 3, 4, 5, 6 and 7 show consecutive stages, 7 shows the bursting and throwing out of the sporangia (spore cases,) anal ogous to the seed vessels, in flowering plants. The species of Uncinula is somewhat similar to (Ediunt Tockeri, which attacks the European vine. The fungus is seen in late summer or autumn show ing on the upper surface of the leaves as white spots, the woolly-leaved varieties being most sub ject to attack, although sometimes the smooth leaved varieties, as Clinton for instance, are not exempt, if the conditions, heat and moisture, are favorable. Fig. 9 shows forms of the genus lawn or microscopic toad stools, formed on a vine leaf bruised to kpulp and fermented. These assume various forms, living and dead organisms having their special forms of parasitic plants. Thus fungus forms attacking a living plant, may continue to exist, or they may attack fruit after it is severed from the parent stem, but decay setting in a different class of fungi appears, that is when vitality is lost and disorganization ensues.