. The descent of man : and selection in relation to sex . Evolution; Natural selection; Heredity; Human beings. REPTILES. first conjecture, which will occur to every one, is that they are used by the males for fighting together; and as these animals are very quarrelsome,™ this is probably a correct view. Mr. T. W. Wood also informs me that he once watched two individuals of C. pumilus, fighting violently on the branch of a tree; they flung their heads about and tried to bite each other; they then rested for a ' time, and afterwards continued their battle. With many lizards, the sexes differ sl
. The descent of man : and selection in relation to sex . Evolution; Natural selection; Heredity; Human beings. REPTILES. first conjecture, which will occur to every one, is that they are used by the males for fighting together; and as these animals are very quarrelsome,™ this is probably a correct view. Mr. T. W. Wood also informs me that he once watched two individuals of C. pumilus, fighting violently on the branch of a tree; they flung their heads about and tried to bite each other; they then rested for a ' time, and afterwards continued their battle. With many lizards, the sexes differ slightly in color, the tints and stripes of the males be- ing brighter and more distinctly defined, than in the females. This, for instance, is the case with the above Cophotis and with the Acantho- dactylus capensis of S. Africa. In a Cordylus of the latter country, the male is either much red- der or greener than the female. In the Indian Calotes nigrilabris there is a still greater difference; the lips also of the male are black, whilst those of the female are green. In our common little viviparous lizard (Zootoca vivipara) "the under "side of the body and base of the tail in the male are bright ''orange, spotted with black; in the female these parts are pale- "grayish-green without spots.'"" We have seen that the males alone of Sitana possess a throat-pouch; and this is splendidly tinted with blue, black, and red. In the Proctotretus tenuis of Chile the male alone is marked with spots of blue, green, and cop- pery-red.'^ In many cases the males retain the same colors throughout the year, but in others they become much brighter dur- ing the breeding-season; I may give as an additional instance the Calotes maria, which at this season has a bright red head, the rest of the body being ;. '""^iili^ Fig 36. Chamaeleon Owenii. Upper figure, male; lower figure, female. «» Dr. Bucholz, 'Monatsbericht K. Preuss. Akad.' Jan. 1874, p. 78.
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Keywords: ., bookcentury1800, bookdecade1870, booksubjecthumanbeings, bookyear
