The formation of the spermatozoa in the interior of independent cells of developement likewise takes place in a similar manner in the Lacerta crocea. We have but rarely seen that the sante cells are enveloped by larger cysts at the period of the production of the spermatozoa, which is commonly the case in former stages of the development. The num ber of cells contained in one common cyst is generally only very small, seldom exceeding eight. The same is found, according to the end itself does not however participate in this formation. It is of a more delicate quality, paler, and has a constant vibrating motion, which gives to it a varying form. It generally appears to be wound in an undulating manner.
A fascicular group of the spermatozoa is only found among the Reptilia in Batra chians ; Bombinator, however, forming an ex ception. In the latter, as well as in the scaly Reptilia, the spermatozoa lie confusedly toge ther. In the latter' instances we can readily trace their production in the interior of se parate solitary cells of developement ; as, for instance, in Anguis fragilis, or Bombinator igneus. The cells of developement of the latter animal (which to the number of two or four are enclosed by a mother cell, when in the earlier stages of developement) mea sure in a developed state about -r-W". At first, when the spermatozoon forms itself in the interior of these cells, it lies curled up close to the wall. ' Subsequently the fibre stretches itself, and changes the cell into an obtuse cylindrical enclosure, which finally bursts in the anterior and posterior part, to enable the spermatozoon to make its exit. The remains of observations of Kiilliker, in Testudo grwea ; but the external cyst in this instance is said generally to persist for a longer period. The
persistency of this enclosure is very general among the Batrachians, which distinguish themselves by the spermatozoa being asso ciated in fasciculate groups. The number of the enclosed cells of developement here is generally a larger one (from ten to twenty). The developement of the spermatozoa in other respects does not, however, exhibit anything peculiar. They are formed as usual, separately in the enclosed cells of de velopement (fig. 344.). It is only afterwards, when these cells have been dissolved, that the spermatozoa get into the interior of the mother cyst, in which they congregate in fitsciculate groups. By their so doing the cyst loses its original round shape, and as sumes the form of a pear, until it bursts at the pointed extremity, and the tail-ends of the spermatozoa immediately project. The re mains of the cyst continue recognisable for some time at the anterior end of each bundle. This is the case in the frog at any rate. In Pelobates, on the other hand, the filiform tails of the spermatozoa do not project from that part of the cylindrical enclosure which is burst, but the anterior vibrating body does so ( fig. 345.).
The external cyst of the bundles of sperma tozoa of the Salamander constantly retain its original globular shape, as the sperma tozoa do not stretch but remain wrapped up. It is a remarkable sight to see the cyst burst The spermatozoa of Scymnus nicensis (fig. 349. A) are similar but rather longer, whilst ing on being treated with water. The whole mass of spermatozoa suddenly bursts forth, and only remain attached to each other by the heads, as if imbedded in one common sub stance. The separate fibres radiate in all direc tions, each being wrapped up in a spiral form.