18 



are discussed. 



**. Clark, D. R., 3r. 1976. Ecological observations on a Texas, USA, 

 population of Six-lined Racerunners, Cnemidophorus sexlineatus (Reptil- 

 ia, Lacertilia, Teiidae). JOURNAL OF HERPETOLOGY 10(2): 133-138. 



The activity season lasts from April until October in Brazos Coun- 

 ty. Most females lay 2, some lay 3, clutches per year averaging 3.38 

 eggs. Females reach reproductive maturity at 1 year of age. Population 

 turnover is essentially annual although some individuals did survive the 

 winter. Home ranges for both sexes were similar and averaged 13099 m^. 

 Year to year climatic fluctuations affected population densities, esti- 

 mated at 15-2^^ lizards per hectare, and home range sizes. 



*5. Cole, C. 3. 1975. Evolution of parthenogenetic species of rep- 

 tiles, in INTERSEXUALITY IN THE ANIMAL KINGDOM. Reinboth, R., 

 editor. Springer-Verlag, Berlin in New York. pp. 3^0-355. 



The origin and evolution of parthenospecies is discussed in a 

 general review article. The species of Cnemidophorus discussed include 

 dixoni, exsanguis , flagellicaudus , neomexicanus , sonorae , tesselatus , 

 uniparens and velox . Problems suggested for study include determination 

 of the egg activation mechanism(s), elucidation of the chromosomal me- 

 chanism of sex determination, problems involving gene dosage compensa- 

 tion (as different ploidy levels are involved in Cnemidophorus partheno- 

 species), the influences of mutation rates on parthenospecies compared 

 to sexual ones, and ecological interactions between parthenoforms and 

 sexual species. 



1^6. — . 1979. Chromosome inheritance in parthenogenetic lizards and 

 evolution of allopolyploidy in reptiles. J. OF HEREDITY 70: 95-102. 



Cnemidophorus exsanguis , C. sonorae and_C. tigris from Arizona and 

 New Mexico were raised and crossed in the laboratory. _C. exsanguis from 

 Alamogordo represent two distinct karyotypes (= clones) and these are 

 inherited precisely as demonstrated by rearing several generations from 

 each one in the lab. _C. sonorae (3N) X _C. tigris (IN) produced a viable 

 tetraploid hybrid. The origin of parthenogenetic Cnemidophorus through 

 hybridization and earlier conclusions on the evolution of allopolyploidy 

 in reptiles is confirmed. 



*?. — , C. H. Lowe and 3. W. Wright. 1969. Sex chromosomes in Teiid 

 whiptail lizards, genus Cnemidophorus . AMERICAN MUSEUM NOVI- 

 TATES 2395: 1-U. 



