2 7 6 



convinced myself by opening many specimens, in all of 

 which the intestines were destitute of food. 



When a fish is first hatched, we see a large sac depend- 

 ing from its lower surface, this being the yelk or umbilical 

 sac, in which nourishment is contained, and sustains the 

 young for a longer or shorter period. After this food has 

 been absorbed, the fish culturist frequently finds great 

 difficulty in procuring suitable nourishment for his young 

 charges. 



Fishes are to a great degree highly voracious ; thus, Dr. 

 Houston showed in 1847 at the Zoological Society the 

 skeleton of an angler Lophius piscatorius two and a half 

 feet long. Inside its stomach was the skeleton of a two- 

 feet long cod fish, Gadus morkua, within whose stomach 

 again were contained the skeletons of two whiting, Gadus 

 merlangus, of the ordinary size, while inside the stomach of 

 each of these fish lay numerous half-digested bones of 

 little fishes, which, however, were too small and too com- 

 minuted for it to be possible to identify the species they 

 belonged to. 



In warm-blooded animals a large amount of food is 

 necessary in order to produce the high temperature of the 

 blood, and make up for the wear of the body produced by 

 constant motion. But in cold-blooded forms a different 

 condition exists, in them nutriment being mostly employed 

 for increasing the size of the animal, a much less amount of 

 food being required to sustain the smaller wear and tear 

 resulting from the little motion which is often perceived, 

 especially in fresh-water forms. 



In most of the shallow portions of the sea around our 

 coast are distributed various descriptions of sea weeds. 

 Should the bottom be rocky we find brown algae (Ftici), 

 while further out from the tide line are red algae (Floridt). 



