142 



THE DEVELOPMENT OF THE GAMETES OR SEX CELLS 



CYTOPLASMIC 

 MEMBRANE 

 ACR OSOME 

 VACUOLE 

 NUCLEUS 



POS T- 

 UCLEAR CAP 



ECK GRANULE 

 T E R 10 R 

 CE NT RIOLE 



MEMBRANE 



OCHONDRIAL 

 SHEATH 



TER 10 R OR 

 CE NTRIOLE 



L FILAMENT 

 F TAIL 



Fig. 77. Spatula-type sperm of various mammals. (Compiled from Bowen; Gatenby 

 and Beams; Gatenby and Woodger; see references in bibliography.) Observe the vacuole 

 inside the head of the sperm. Gatenby and Beams found that this vacuole, in some 

 instances, stains similar to a nucleolus, but suggest it may be a hydrostatic organ, or 

 respiratory structure. (P. 20, Quart. J. Micr. Sc, 78.) 



suggest their description as "lamp-brush" chromosomes. Another difference 

 of chromatic behavior is manifested by the fact that the chromosomes in the 

 developing female gamete during the diplotene stage are not easily stained 

 by the ordinary nuclear stains, whereas the chromosomes in the spermatocyte 

 stain readily. 



Aside from the differences in chromosomal behavior, great discrepancies 

 in the amount of growth of the nucleus occur in the two gametes during meiosis. 

 The nucleus of the oocyte greatly increases in size and a large quantity of 

 nuclear fluid or sap comes to surround the chromosomes (figs. 7 IF, G; 72C, 

 F, E). Correlated with this increase in nuclear size, the egg grows rapidly, 



