NATIONAL FISHERY CONGRESS. 197 



attains considerable dimensions is "eaten as living macaroni." This statement of 

 Leuckart's has been taken without question and repeated in various forms by different 

 writers. Donuadieu (Contribution a 1'histoire de la Ligule, Journal d'Anatomie et de 

 la Physiologic 1877) repeats the assertion and adds that many people in Lyons have 

 the same habit. Doubtless the truth is that ligulae have been eaten along with the 

 fish which harbored them, much as roe is eaten, by persons who did not know the 

 real nature of the tidbit, which no doubt, in the blissful ignorance of the eater, 

 pleased his palate quite as well as did the flesh which was a part of the fish. 



ACANTHOCEPHALAJ 



The members of this order, so far as my observation goes, are not found in large 

 numbers in many species of fish, although they are likely to occur in great number in 

 occasional individual hosts, particularly among the flounders ( Pleuronectidce). The 

 most persistently occurring cases of parasitism which I have observed, however, have 

 been in this order. I have examined the striped bass (Roccus lineatus) repeatedly in 

 successive summers at Woods Hole, Massachusetts, and have rarely found an indi- 

 vidual which was not infested with a thorn-head worm (Echinorhynchus proteus). 

 Sometimes it occurs in considerable numbers, and almost always penetrates with its 

 thorny proboscis the coats of the intestine of its host, thus causing more or less local 

 irritation, followed by a waxy degeneration of the tissues. 



There is probably no practical way of counteracting the bad influences of worms 

 of this order, since their larval state is passed, in some cases certainly, and in most 

 cases probably, in small Crustacea, which constitute a constant and necessary source 

 of food for the fish. The same remark which was made in another connection with 

 regard to the disposal of the viscera of fish applies here. In no case should the 

 viscera of fish be thrown back into the water. In this order the sexes are distinct, and 

 the females become at last veritable sacs for the shelter and nourishment of enormous 

 numbers of embryos. The importance, therefore, of arresting the development of as 

 many embryos as possible is at once apparent. 



NEMATODA. 2 



The round worms are very abundant, especially in immature stages, in marine 

 fishes. In fresh-water fishes they are probably not so abundant. 



I have lately gone over a large collection of nematode parasites of fishes, made in 

 part by myself at Woods Hole, Massachusetts, and in part belonging to the United 

 States National Museum, having been collected in various localities. In this collection 

 there are nematodes from over 60 species of fish. I have noted some 80 distinct kinds, 

 14 of which have to be recorded as "Ascaris species," they being immature, although free 

 in the intestines of their hosts. They plainly belong to the genus Ascaris, but do not 

 have distinct characters which will enable one to refer them to species already estab 

 lished or to make it advisable to give them new specific names. At least 40 kinds, 

 from as many specifically different hosts, I have been obliged to refer to a section 

 headed u Immature nematodes, encapsuled, and for the most part belonging to the 

 genus Ascaria." It would not be profitable to give names to these immature forms, 

 since many of them are doubtless different stages in the development of the same 



1 See list of authorities: No. 7, pp. 490-498, pi. v, vi; No. 9; No. 13, pp. 555-556, pi. .65-67. 

 * See list of authorities: No. 13, pp. 557-561, pi. 67; No. 14, pp. 111-112. 



