REPTILIAN SPERMATOGENESIS 285 



The same general arrangement is retained through the matura- 

 tion divisions and is typical for all Iguanidae studied. For 

 convenience in the description and the discussion, the term ' macro- 

 chromosome' has been adopted to designate the large V-shaped 

 bodies, and the term 'micro-chromosome' has been applied to 

 the small dot-like bodies. It should be emphasized, however, 

 that the use of these terms is for convenience in descriptions, 

 and that no physiological or functional difference between the 

 macro- and micro-chromosomes is implied. Indeed, in one 

 species studied, there is really no very sharp line to be drawn 

 between the two sets of bodies, and in every case both types be? 

 have in the same way, except for the sex-chromosomes. 



The Iguanidae proved to be the most favorable family for 

 study, and among the species examined Anolis carolinensis and 

 Sceloporus spinosus gave the best preparations. 



The local fauna around Austin is rich in genera and species 

 for several families of lizards. ]Material has been preserved 

 and studied for the following species, common local names are 

 indicated : 



Anolis carolinensis, 'American chameleon' 



Holbrookia texana, 'Zebra-tail lizard' 



Crotaphytus collaris, 'Mountain boomer' 



Uta ornata, 'Rock lizard' 



Sceloporus spinosus, 'Tree lizard' 



Sceloporus undulatus consobrinus, Rare 

 Cneminophorus gularis, 'Race runner' 



Phrynosoma cornutum, 'Horned toad' 



Gerrhonotus liocephalus, * Rare 



In the following pages the spermatogenesis of the first seven 

 species will be given. Much time has been spent preserving 

 and studying the testes of the 'horned toad,' but no first-class 

 preparations were obtained. The same may be said also of 

 Gerrhonotus, but only one male of this species was examined, 

 and he was too mature to be favorable for study. 



