" In December and January, the male ova become larger, their nuclei show distinctly two nucleoli: the granular cells have multiplied, and some show characteristic signs of segmentation. At this moment, the male ova are immersed in numerous granular cells, which are occasionally multiplied sufficiently to completely surround the ova.
" In February, and the first days of March, the male ova become very large, and, at the same time, their nuclei segment. A section of the semi niferous canals, examined at this period, shows that the fascia of sperma tozoids are no longer regularly attached to the wall of the canal, but that they are floating in the cavity of the latter. But what is most remarkable, in a section at this period, is the appearance of an epithelium with large cells (08) (fig. 71) which covers the walls. By the aid of a higher power we find that this epithelium is formed simply of large male ova, the nuclei of which are more or less advanced in their segmentation.
" During the whole of the months of March and April, the seminiferous canaliculi present this same appearance (see Figs. 70 and 71). Around each of these male ova are placed granular cells (G), some in contact with the wall of the canal, others on the projecting parts of the male ova, that - is, on the parts towards the centre of the canal. But these granular cells are never abundant enough to cover the whole surface of the male ova, to form about each one of them a layer, or, as some writers have said, a complete envelope.
"In May and June, we have only to note the continuation of the seg mentation of the nuclei of the male ova, and the augmentation in volume of these ova. To the appearance of a regular epithelium on the walls of the canaliculi, has succeeded that of a series of irregular projecting bodies of different sizes, but in which it is easy to recognize male ova, provided with a great number of nuclei. When these elements have attained this degree of development, it is difficult to keep the name of male ova, and we will, at the end of this period, call them spermatic cysts.
"Among these spermatic cysts are yet found male ova less advanced in their phase of nuclear segmentation, that is, there are all forms of transi tion between male ova and spermatic cysts.
" In June, the spermatic cysts are so large that they project towards the central portion of the lumen of the canal.
" From the first days of July, the disposition of the nuclei in the spermatic cysts takes a very peculiar aspect. The nuclei all pass towards the periphery, and are there ranged in a single, regular layer. The centre of the cysts is then formed of a homogeneous and finely granular protoplasm.
" During the last of July and August, there occurs a sort of rarefaction of protoplasm in the portion of the cysts that points towards the centre of the seminiferous canaliculi, that is, in the free portion of the cysts. The limits of the cystic cell, clearly defined in the zone of the nuclei, become indefinite at this central extremity, from which the nuclei retire to a small portion. Soon the cyst appears as if open at this point. Now, and occasionally before, the protoplasm of the cystic cell begins to con dense into bands placed in a radiating manner, that is to say, springing from the peripheral zone of nuclei and converging toward the centre.
" When this sort of dehiscence is well marked, we find, during the month of September, a more distinct disposition of the protoplasm in radiating bands, and a modification of the nuclei which are still peripheral. First, the protoplasm forms triangular bands, the internal end of which is slender and ill-defined, the external end of which is thicker, forming an inflated and obscure portion, and which blends with the peripheral pro toplasm that surrounds the nuclei. Secondly, these nuclei appear to lengthen, and look like a drum-stick, and, in the ultimate transformation, we will show that these little knobs represent the heads of spermatozoids.
" In September,the spermatic cysts form a pouch,the walls of which have a layer in which the heads of the spermatozoa, which are forming, lie reg- 1 ularly alongside of each other. This pouch, free at its central and up per portion, has its intermediate zone occupied by delicate bands of pro toplasm, each of which corresponds to a future spermatozoOn.