PARASITES OP THE SALMON OF THE TAT. 153 



a good illustration. In a salmon of ten pounds, a BothriocepLalus 

 lay coiled in tlie duodenum, and passing down to the small intes- 

 tine filled it even to distention. The anterioi' portion proceeded 

 into a caecum by a double coil ; from this, other four plies (two coils) 

 entered another caecum close by the pylorus, and performed many 

 intricate bends therein, filling out the sac to a size equal to the 

 similarly distended intestine of the fish. This csecum contained 

 the head, the distance of which from the trimcated posterior ex- 

 tremity was 6 feet 6 inches. About 20 inches from the head a 

 narrowing of the segments occurred, so as to resemble those near 

 the head, — a not unfrequent occurrence. The size of the ]3othrio- 

 cephali did not always bear comparison with that of the fish. 



Ascaris capsularia (Eud.). — This species is easily recognized 

 by a whitish opaque portion a little behind the head. It is found 

 on the liver, pyloric caeca, stomach, intestines, and gall-bladder at 

 the attachment of the mesentery, &c. It is enveloped in a cap- 

 sule of delicate fibrous tissue, in which it lies as a finger in a glove, 

 — a circumstance which, from the attachment of the capsule to the 

 surrounding textures by many delicate fibrous bands, renders it 

 difficult to pull the creature ofi" rudely or en masse, while it can 

 readily be unhoused by dravraig at its free end. These Ascari 

 occur in most grilse and salmon ; in fact, it is exceptional to find 

 them absent. On the liver they are met with on all parts of the 

 surface, coiled in a circular depression of its texture, but with a 

 portion of the latter projecting in the centre. Most form this close 

 coil, but others stretch in a long curve or semicircle. In the former 

 the head is always external. On the caeca they are found amongst 

 the iat, coiled after the fashion of a nummulite, and often sur- 

 rounded by a deposit of pigment. Occasionally one had the an- 

 terior part of the body pushed into a caecum, or, rarely, into the 

 tissue of the liver. Once, on examining a small eminence on the 

 inner surface of the stomach, a living Ascaris capsularia emerged 

 on squeezing the perforated sunjmit. Earely one or two occurred 

 in the interior of the stomach and intestines. Attached to the 

 pyloric caeca, where these are so frequently found, curious struc- 

 tirres which seemed degenerated Ascari were sometimes met with. 

 A calcareous deposit filled part of the interior of one example. 



Other forms of Ascarides * were present, some of which appeared 

 referable to undescribed species. It may also be noted that in 

 the stomach I once met with several small fibro-cartilaginous 



* One species especially occurred veiy frequently,, 



