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rich muddy bottom, in which he bores with his head in 
the search for worms, larvae, &c., on which, together 
with grass, young rushes, other vegetable substances, 
animal excrements, swollen barley, kitchen refuse, &c., 
he subsists.” Not satisfied with the results of manage- 
ment based on these theories of the habits of the carp, 
Susta undertook in 1876 a systematic study of the con- 
tents of the alimentary canal of the carp. Hundreds of 
specimens, from many different ponds, under various 
systems of feeding, were dissected and the results of the 
inspection carefully noted, with evident faithfulness and 
candor. Asa result he reached the conclusion that the 
carp in reality subsists on animal food exclusively ; and 
that the vegetable constituents of the contents of the 
stomach and intestine could only have been swallowed 
by accident, and in fact were voided by the fish almost 
wholly unaffected by digestion. 
Susta extended his investigations to other species and 
found only three sorts which could be considered plant- 
feeders. He classifies the ordinary European pond-fish 
aside from the carp, on the basis of their food, into (A) 
fish of.prey : (B) eaters of small animals: (C) vege- 
tarian. 
In the category of fish of prey, he names the pike, 
perch, ruff, (a percoid), pikeperch, brook trout, eelpout 
(Lota), sheat fish (Sedurus), and eels. As eaters of 
minute animals, he gives us the maraena (Coregonus), 
cruciancarp, tench, gudgeon, and eight other species of 
cyprinoids His list of vegetarians comprises only three 
species, namely, the dobule. (Sgualius dobula, Heck), the 
roach ( Leucescus rutzlus, Heck), and the rudd (Scardin- 
zus erythrophthalmus, Bon), all cyprinoids. 
More recently Dr. Otto Zacharias, director of the 
biological station at Plon, has made similar investigations 
of the stomach contents of numerous species of fish and 
reached the conclusion that the above three species are 
the only vegetarians among them ; and the researches 
