238 SEA-SIDE STUDIE& 



effect of a mere exaltation of animal heat upon the instincts 

 and affections of the different races of the Vertebrata. The 

 fishes absolutely unable to assist in the maturation of their 

 offspring, are content to cast their spawn into the water, and 

 remain utterly careless of the progeny to be derived from it. 

 The reptile, equally incapable of appreciating the pleasures 

 connected with maternal care, is content to leave her ejrffs 

 exposed to the genial warmth of the sun until the included 

 young escape. But no sooner does the vital heat of the 

 parent become sufficient for the purpose designed by Natui'e, 

 than all the sympathies of parental fondness become deve- 

 loped." * This is a very plausible generalisation ; but there 

 are facts which peremptorily contradict it. On the one 

 hand, there are cold-blooded vertebrates — fishes, such as the 

 Hassar, Goramy, Stickleback, Lepidogaster, and Syngnathus 

 — which make nests, or sit on their eggs. On the other 

 hand, there are warm-blooded vertebrates — birds, such as 

 the cuckoo and American cowbird, which, utterly regardless 

 of maternal delights, leave their eggs to be hatched by other 

 birds. 



The fishes contradict our generalisations on many other 

 topics ; and a very curious passage in Natural History might 

 be written by any one who should take the trouble to 

 collect and group together what may be called fish-paradoxes. 

 Thus there are fish that fly ; fish that climb (Percha scan- 

 dens) ; fish tliat hop, like frogs, using their fins as veritable 

 legs (Lophius) ; fish that ruminate {the carp) ; fish that 



' Rtmer Jones, General Outline of the Animal Kingdom, p. 615. 



