102 THE FUR SEALS OP THE PKIBILOP ISLANDS. 



ulcerations were so extensive that it is curious the animal should have survived so 

 long." In another portion of his report Murie, in referring to the abscess of the brain, 

 remarks: "Whether this lesion was the more immediate cause of death, and not the 

 ulcerated condition of the stomach, is an open question." 



Admitting that the ulcerated condition of the stomach was caused by the worms, 

 and admitting that with "only the muscular and a very thin lining of the submucous 

 tissue" remaining perforation might have easily occurred and been followed by a fatal 

 peritonitis, we fail to see that Murie has made a clear case in diagnosing the cause of 

 death. 



Oobbold (1879) devotes a portion of his work on "Parasites" to a discussion of 

 the animal parasites of Pinnipedia (Part V, pp. 313-315) and Oetacea (Part XI, pp. 

 416-430), from which the following passages are extracted: 



Cobbold, 1879, page 418 : The apparently healthy cetacean IPhocaeaa communis = Phocaena phocaena^ 

 was shot by Mr. Jardine Murray in the Firth of Forth in April, 1855. I mention its condition because 

 the bile ducts were found to be diseased in a way similar to that ordinarily observed in cases of 

 fluke rot affecting sheep, cattle, and other animals. In my MS. note book I remarked: "The liver 

 ducts were in several places thickened and knotted near the surface of the organ. On opening these 

 they were found to be loaded with small distomata" [Distoma Campula=Campula oblonga], 



Cobbold, 1879, p. 422 : » » » The small intestine of this porpoise [i)eZ^Awmsj))iocoe»ai=PAocfle«a 

 phoeaena] was completely choked for the space of 8 or 9 feet by fine tapeworms so closely packed 

 together that the gut presented the appearance of a solid cylinder. 



A most remarkable infection of a Olobicephalus Svineval (=Globlicephala melas) 

 with thorn-headed worms {Echinorhynchus capitatus) was reported by Parona (1893), 

 who estimated that 25,305 specimens were present in the intestine. Parona does 

 not give a detailed account of the pathological effects of this infection, nor of any 

 symptoms observed by the captors, but argues in favor of the view that a heavy 

 infection like this one must have the same effect upon a wild animal as upon a 

 domesticated animal. 



These four citations are the most important references we have found dealing 

 with the effects of parasitic worms upon marine mammals. It might, however, be 

 added that the supposed genus Gonocephalus (see Ascaris typica, p. 127) was based 

 upon a coagulated body formed by mucus and epithelial cells from the stomach of 

 the host; but the relation of the worms to any possible erosion of the stomach wall is 

 not mentioned. 



As it is impossible, in the time alloted to the preparation of this report, to discuss 

 in detail all of the different parasites we find recorded for marine mammals, our 

 discussion will be confined to forms directly bearing upon the parasites collected by 

 Mr. Lucas. 



THE PARASITIC WOKMS COLLECTED BY LUCAS IN BERING SEA. 



Mr. Lucas has furnished us with the following data concerning his examinations 

 of marine mammals in Bering Sea during the summer of 1896: 



Nematodes in varying numbers are always present in the stomach of the fur seal. There may be 

 only two or three or there may be, roughly speaking, one hundred or more. Only in rare cases does 

 their presence seem to cause any irritation, but occasionally a number may be found attached to one 

 spot, and the stomach wall is there thick and hard. 



An extreme case of this is shown in the specimen of stomach of sea lion, Eumetopias, but no case 

 so bad as this was met with in any fur seal. The tapeworm is found in about two out of every five 

 seals. Sometimes but one is present, sometimes ten or a dozen, though so many as this is rare. 



