298 THEOPHILUS S. PAINTER 



phorus represents an entirely different family from the lizards 

 so far described, a fragmentary account of the spermatogenesis 

 will be included here. 



Spermatogonia! divisions have been studied, but th6 number 

 of chromosomes involved and the poor fixation made it impossible 

 to determine even the approximate number of these elements. 



The early history of the first spermatocytes was followed in 

 some detail, and was found to differ in no way from what had 

 been observed in Anolis carolinensis. Two large nucleoli are 

 seen in the 'diffuse' nucleus; these diminish in size as the lepto- 

 tene threads appear. In early prophase stages the chromosomes 

 generally appear as rounded masses, and one cannot see the 

 formation of tetrads, as could be done in the family Iguanidae. 

 This is due to the faulty fixation of my material. 



In the primary spermatocyte division stages the chromosomes 

 appear as rounded masses of varying size (text fig. 4, A and B) 

 about twenty in number. Of these, thirteen are large, while 

 seven are much smaller. It will be seen from the figures, how- 

 ever, that the large and small chromosomes intergrade in size 

 and we do not have sharp division into macro- and micro- 

 chromosomes such as was found in the family Iguanidae. 



In side views of the first spermatocyte spindles one occasionally 

 finds cells such as are shown in text figure 4, C and D. A bipar- 

 tite body lies to one side of the spindle, well advanced (text 

 fig. 4, C) toward one pole. This element is very suggestive of 

 the X-element found among the other lizards studied, but I 

 was unable to make counts of anaphase stages, so that this 

 point could not be verified. 



In the second spermatocyte division (text fig. 4, E and F) the 

 chromosomes have fused together, so that accurate counting 

 is out of the question. This fusion of elements is, perhaps, 

 similar to the 'double reduction' reported in the second sper- 

 matocytes of birds and of some mammals. Cnemidophorus is 

 the only lizard, out of seven species studied, in which I obtained 

 such fusion. The chromatin masses vary in number from five 

 up to ten or more, the variation being due to more or less general 

 fusion of the nineteen or more chromosomes which were handed 



