33 



89. Goldberg, S. R. and C. H. Lowe. 1966. The reproductive cycle of 

 the Western Whiptail lizard (Cnemidophorus tigris ) in southern Arizona. 

 JOURNAL OF MORPHOLOGY I18(^): 5if 3-5^8. 



Lizards f ronn near Tucson, Pima County, undergo a seasonal cycle in 

 which gonadal size is nninimal in September-October. Male reproductive 

 organs gradually recrudesce during the winter months spent underground. 

 After they emerge from hibernation in March-April the testis, seminifer- 

 ous epithelial height and tubule diameter gradually increase in size 

 through April and May, reaching maximum size in June-July followed by 

 rapid regression in August. Mating is first observed in the field in 

 May. The ovaries undergo a period of heavy yolk deposition from early 

 April to May, and remain functional until August. A thick circumtesti- 

 cular subtunic layer of equivalent interstitial material (Leydig cells) 

 is reported and described for the genus. 



90. Gorman, G. C. 1970. Chromosomes and the systematics of the 

 family Teiidae (Sauria, Reptilia). COPEIA 1970(2): 230-2^*5. 



Teiids have undergone an extensive adaptive radiation. There are 

 about W living genera with a total of some 175 species. If chromosome 

 data alone were used, one would definitely consider the family to be of 

 South American origin. The fossil record shows that such an interpre- 

 tation is unwarranted. There was a rich and diverse macroteiid fauna 

 during the Cretaceous in North America with all modern lineages repre- 

 sented. Teiid diversity appears to have dropped drastically in North 

 America following the Cretaceous, for the only positive identifications 

 are of Cnemidopho rus-like species. Thus the present distribution of 

 the Teiidae is one of range shift or contraction. It is possible that 

 the loss of climatic equability toward the end of the Cretaceous, pos- 

 tulated to account for dinosaur extinction, eliminated from North Amer- 

 ica all teiids that were not adapted to xeric conditions. Absence of a 

 Cenozoic land bridge until the Pliocene slowed recolonization of North 

 America by South American teiids. Although Cnemidophorus- like lizards 

 have been in North America from at least the early Miocene, they have 

 not been the source of a major adaptive radiation. This may not be due 

 to lack of time, but to the rigid specialization of Cnemidophorus to an 

 open niche with high insolation. 



91. — , Y. J. Kim and C. E. Taylor. 1977. Genetic variation in ir- 

 radiated and control populations of Cnemidophorus tigris (Sauria, Tei- 

 idae) from Mercury, Nevada, with a discussion of genetic variability in 

 lizards. THEORETICAL AND APPLIED GENETICS ^^9(1): 9-[i^. 



A fenced population that had been irradiated for 10 years was 

 studied, as was a fenced non-irradiated and a free-ranging population. 



