46 J. BRONTE GATENBY 



large yolk-spheres (y) and Hinaller fuchsinophile bodies, possibly mito- 

 chondrial in nature (m). ch.k. 



Fig. 2. — Younger spermatocyte from a Mann-Kopsch preparation, show- 

 ing at X a number (about two) of largish spheres, believed to be identical 

 with the same bodies marked x in figs. 9, 10, and 11, and which seem to 

 take some part in the formation of the tail skeleton of the sperm. At y 

 are the yolk-granules, and at oa the Golgi apparatus ; compare this with 

 fig. 1, in which the apparatus is formed of delicate slightly-curved rods. 

 In fig. 2 the rods arc heavily impregnated with OsOi, and possibly owing 

 to a shrinkage of the centrosphere, they have become much more curved. 

 The mitochondria do not show. m.k. 



Fig. 3. — Cell of the spermatocyte series but showing a modification ; 

 the mitochondria are small, like those of the egg (fig. 24), and peri-nuclear 

 bodies are present at nlx (compare with egg in fig. 23). At y is a group 

 of yolk-spheres. CH.K. 



Fig. 4. — Metaphase of second spermatocyte division. Note alteration 

 in shape of mitochondria (m), which from their previous granular structure 

 (fig. 1) have become filiform. At Y the group of yolk-spheres has lx»come 

 grouped near the spindle preparatory to being sorted out into two groups 

 as in the next figure. At XY are bodies supposed to be Golgi elements 

 stuck on the poles of the asters. 



Fig. .5. — Telophase of second spermatocyte division, the equatorial plate, 

 is forming, and the mitochondria, still filamentous, are grouped near in 

 a special manner, being most numerous near the forming cell-wall. At 

 y are the yolk-spheres, now sorted out into two groups, ch.k. 



Fig. 6. — Spermatocyte, for comparison with the oocytes in fig. 20. m.k. 

 Scale above. 



Fig. 7. — Spermatogonium drawn to same scale as spermatocyte in fig. 1 . 

 Shows Golgi apparatus consisting of from eight to ten dictyosomes or 

 rods, a spindle-bridge at SB, and the mitochondria at M, grouped near 

 the centrosphere. m.k., counter-stained in Aitmann. 



Plate 2. 



Fig. 8. — Newly-formed spermatid, showing the Golgi apparatus some- 

 what scattered on the right and the mitochondria surrounding the nucleus. 

 The yolk-granules form a compact group at Y. The centrosome would be 

 on the right side of the nucleus, ch.k. 



Fig. 9. — Later spermatid after the outgrowth of the axial filament. 

 The spheres at x are probably of the same nature as those drawn in PI. 1. 

 fig. 2. The mitochondria have now become grouped behind the nucleus 

 at M, while the Golgi elements (ca) and yolk-spheres (y) have drifted to 

 the bottom of the elongating cell. The cytoplasm, as in many Kopsch 

 (OsOi) preparations, is coarsely fibrillar. At GX is a body believed to be 

 forming the acrosome. m.k.. counter-stained in Altmann. 



