62 Part III. — Tiuenty- eighth Annual Report 



into water, either sea water or fresh water, it swelled up and became 

 plump. It then gradually turned white. Shortly after the worm was put 

 into the water a little movement was detected in one or two cases, but there 

 was no clear evidence that the nematodes were alive. After they had been 

 some time in the water no further movement was detected. Even when 

 alive these worms are often very sluggish. 



Sand-eels ( Ammodijtes sp.) and an Hermit-Crab ( Eupagurus hernhardiis) 

 eneyi^ted in the abdominal cavity of the Haddock ( Gadus ceglefinus), God 

 (Gadus callariasj, and Saithe (Gadus virens). Figs. 35, 38, 39, 40, 44. 



A number of examples of this condition have been obtained among fish 

 landed in Aberdeen. They have been kindly supplied by Mr. B. 

 Erlandsson. 



The sand-eels, after being swallowed by the fish, have escaped from the 

 gut and passed into the abdominal cavity. There they have generally 

 damaged the liver before they died. Sometimes they are found with the 

 head or tail jammed tightly into the space between the reproductive organ 

 and the peritoneum. They are covered with a material which resembles a 

 hardened paste, and in some cases they are in part enclosed in a skin of 

 connective tissue derived from the peritoneum. In this way they are 

 reduced to a mummified condition. 



The fishes, which had acted as hosts, had all been gutted ; an opportunity 

 did not therefore occur of seeing the condition of the gut. 



One large sand-eel was most commonly found in the cavity, but in one 

 case three small sand-eels were present. 



Fig. 38 (Haddock, 6 Feb. 1909), represents a condition where the sand-eel 

 (s.) 6| inches (16'5 cm.) long had pushed its head through the liver (l.) 

 Posteriorly the fish was attaciied to the peritoneum and to a portion of 

 damaged tissue {g.) 



Fig. 39 (Haddock, 19 May 1909). In this case the head of the sand-eel 

 was directed posteriorly. The tail had been pushed into the liver which had 

 become attached {at.) to the peritoneum. Beneath the middle portion of 

 the fish, that is, between it and the peritoneum, there is only a shred of 

 liver tissue. The sand-eel was covered with a paint-like coat. 



Fig. 40 (Haddock, 4 October 1909). Three small sand-eels, measuring 2^ 

 or 2| inches (6-7 cm.) long, («.', s.", s.'") were free in the abdomen. 

 The ovary is much shrunk and wrinkled as if it had been a spent. Two of 

 the sand-eels had their heads tucked in between the ovary and the wall of 

 the abdomen. The ureter (ur.) was severed from the urinary bladder {ur. 

 hi.), but that may have been done when the fish was gutted. The ovary 

 had become attached to the peritoneum along the edge (at.). 



Fig. 35 (Cod, 22 May 1909). The cod measured about 24 inches (60 cm.) 

 in length. The sand-eel (s.) had poked its head into the loose peritoneum on 

 the outer side of the testis. Small cycloid scales could be made out in the 

 skin of the sand-eel which was completely dried. 



Fig. 44 (Cod, 24 Sept. 1909). The sand-eel had in this case destroyed 

 the liver, which is in three detached portions (/., L' I."). The portions (1. 

 and Z.") seem healthy. The part {I') is very dark, and unhealthy looking. 

 The portion of liver in the anterior part of the cavity was enclosed in a 

 loose skin {sk.) which was attached to the peritoneum and swim-bladder. 

 In the normal condition the liver is here quite free from any attachment to 

 these parts. The liver was as it were in a pouch. The sand-eel lay with its 

 head pointed anteriorly, and having its tail poked into the mesentery 

 between the two ovaries (ov.). There are additional growths of tissue 

 attached to the peritoneum at (x.). The piece of liver is also attached to 

 the peritoneum. Where new tissue is superimposed on the peritoneum the 

 pigment dots in the latter are concealed or are only faintly visible, 



