TY - JOUR
AU - Mayr, Ernst
AB - NOTES AND COMMENT had a very similar experience with some mate­ but the genetical evidence is clear in several spe­ rial of Ornithorhynchus. In neither case were cies). One would very much like to know the sex chromosomes identified, but in view of the position in the various orders of Reptiles, par­ poor fixation of the material, this was in­ ticularly in view of the fact that the Turtles are evitable. The problem of the heterogamety of suspected, on morphological grounds, of being the Monotremes is thus still unsolved. somewhat closer to the mammalian stock than The Mammals are thus the only class of the other reptiles. Unfortunately, the cytologi­ vertebrates in which the sex chromosomes can cal evidence on this point is conflicting. The definitely be identified with complete certainty. Japanese school of cytologists claim to have In the vast maj ority of the species so far studied established the existence of female heterogamety XX, but it is the males are XY, the females in three species of lizards and a species of possible that in a few species the Y chromo­ tortoise, one small chromosome in the female some has been lost from the male sex, which 
TI - COMMENTS ON EVOLUTIONARY LITERATURE
JF - Evolution
DO - 10.1111/j.1558-5646.1949.tb00044.x
DA - 1949-12-01
UR - https://www.deepdyve.com/lp/oxford-university-press/comments-on-evolutionary-literature-ScnrxH3iH1
SP - 381
EP - 386
VL - 3
IS - 4
DP - DeepDyve
ER -