REPTILIAN SPERMATOGENESIS 



297 



Spermatogenesis of Crotaphytus collaris 



The study of this hzard was undertaken to determine the 

 chromosome complex, and no attempt was made to trace out the 

 history of the chromosome elements during maturation. 



There are twelve macro-chromosomes (text fig. 3, A) in the 

 spermatogonial divisions and a number of micro-chromosomes. 

 Among the macro-chromosomes one recognizes the 'a,' 'h,' and 

 'c' elements described for other Iguanidae. 



B C 



Text figure 3 Crotaphytus collaris. A. Dividing spermatogonia. B and 

 C. Equatorial plate of the first maturation division. 



The first spermatocytes contain six large macro-chromosomes 

 and around twelve micro-chromosomes (fig. 3, B and C). 



FAMILY TEIIDAE 



The local representative of this family is the common 'race- 

 runner/ Cnemidophorus gularis, which is perhaps the commonest 

 of all the species of lizards found near Austin. The germ cells 

 of this form, however, have proved very difficult to fix properly, 

 and although cold Flemming and modified Bouin's fluid have been 

 used repeatedly, I have never obtained first-class preparations 

 which would allow me to follow the complete history of the 

 chromosomes through maturation. Since, however, Cnemido- 



