452 



THE DESCENT OF MAN 



swim-bladder." The drumming of the Umbrinas in the 

 European seas is said to be audible from a depth of twenty 

 fathoms; and the fishermen of Eochelle assert "that the 

 males alone make the noise during the spawning time; and 

 that it is possible, by imitating it, to take them without 

 bait."" From this statement, and more especially from 

 the case of Ophidium, it is almost certain that in this, the 

 lowest class of the Vertebrata, as with so many insects and 

 spiders, sound-producing instruments have, at least in some 

 cases, been developed through sexual selection, as a means 

 for bringing the sexes together. 



AMPHIBIANS 



Urodela. — I will begin with the tailed amphibians. The 

 sexes of salamanders or newts often differ much both ia 



Pio. 33.— Triton cristatus (half natural size, from Bell's "British Reptiles"). Upper 

 figure, male during the breeding season; \<mer figure, female. 



color and structure. In some species prehensile claws are 

 developed on the fore-legs of the males during the breeding 



« "Comptes Reudus." Tom. xlvi., 1858, p. 353. Tom. xlvii., 1868, 

 p. 916. Tom. Ut., 1862, p. 393. The noise made by the Umbrinas (Scicma 

 aquila) is said by some authors to be more like that of a flute or organ than 

 drmmning. Dr. Zoutereen, in the Dutch translation of this work (vol. B. 

 p. 36), gives some further particulars on the sounds made by fishes. 



*^ The Rev. C, Kingsley, in "Nature," May, 1870, p. 40. 



