21 



at the same time as controls exposed to long photoperiods. This con- 

 firms that the refractory period (a pause in reproductive activity com- 

 mencing in late summer in nature) is under endogenous control. 



56. Cuellar, O. 1968. Additional evidence for true parthenogenesis 

 in lizards of the genus Cnemidophorus . HERPETOLOGICA 2ii{2): 1^+6-150. 



The reproductive tracts and associated organs were examined in 

 both sexual and parthenogenetic species of Cnemidophorus , including 

 exsanguis , neomexicanus , tesselatus , tigris, uniparens and velox . The 

 fact that 6 of 9 bisexual females had spermatozoa in their reproductive 

 tracts while all 36 of the unisexual females lacked similar evidence of 

 courtship, reasonably excludes gynogenesis, a cryptic male behavior, and 

 differential male and female activity periods as interpretations for the 

 all-female condition, and supports true parthenogenesis as the most pro- 

 bable mechanism. Seminal receptacles were absent in both the bisexual 

 and unisexual lizards examined. Sex ratios reported for natural popula- 

 tions of bisexual species of Cnemidophorus are biased in favor of males. 

 This may explain the lack of seminal receptacles in these species. An 

 excess of males might serve the same function as stored sperm, namely 

 to insure a maximum realization of reproductive potential. 



57. -. 1970. Egg transport in lizards. 3. MORPHOLOGY 130: 129-136. 



The morphological cycle of the ovaries and oviducts is examined in 

 individuals of Cnemidophorus exsanguis, _C. inornatus, C. neomexicanus, 

 C. tesselatus, _C. tigris , C. uniparens and _C. velox throughout the re- 

 productive period. Ovaries proceed from a regressed state to a point 

 where they are isolated from the coelom by encapsulating oviducts. An 

 intimate association is established between the oocytes and the infun- 

 dibular oviductal ostia. Photomicrographs are presented. 



58. — . 1971. Reproduction and the mechanism of meiotic restitutuion 

 in the parthenogenetic lizard Cnemidophorus uniparens . 3. MORPHOLOGY 

 133(2): 139-166. 



Live capture methods and captive maintenance techniques for speci- 

 mens from Arizona and New Mexico are discussed at length. The Bosque 

 del Apache (Socorro Co., NM) population exhibited a mean clutch cycle of 

 23 days, with a mean number of 3.3 ova per clutch. The reproductive 

 season in nature terminates at the end of July. Chromosomal and cellu- 

 lar behavior associated with egg production is examined in great detail. 

 Parthenogenesis in this species is of the meiotic type. The somatic 

 number of chromosomes is doubled early in oogenesis presumably by a pre- 

 meiotic endoduplication, and the 3N level is restored by 2 subsequent 

 maturation divisions. 



