214 



Appendices to Fourth Annual Report 



the eggs. Although I have trawled a good deal both in the shore water 

 amidst the haunts of this species, as well as in the deeper parts of St 

 Andrews Bay, not a single example of the Thornback's purse with either 

 eggs or embryo in its interior has been captured. Moreover, no further 

 shelter seems to be necessary for the perfection of the egg than a friendly 

 reach of shifting sand, on and even occasionally in which egg, embryo, 

 and adult find all that is necessary for 'their welfare. A few days after 

 the late severe storm (29th Nov.) a large number of the egg-cases of this 

 species was found on the west sands. The fresh purses (containing living 

 embryos) are easily recognised, as a rule, by their olive colour and greater 

 elasticity, as compared with the blackish empty forms. The interior of 

 the fresh capsule presents a smooth glistening whitish coat, enclosing the 

 translucent gelatinous albuminous fluid. The embryo does not appear to 

 be inconvenienced to any serious extent, though a considerable quantity of 

 sand gains admittance. These ' purses ' form a most effecient protection 

 to the embryos on the ground selected for their deposition, which, of 

 course, is that frequented by the adult. 



On the Habits of Young Food Fishes. — Young food fishes are numerous 

 in inshore water, though, as formerly shown,* the young of both round 

 and flat fishes are found in deep water. Thus a considerable proportion 

 (about nine-tenths) of the total number of immature fishes caught during 

 the investigations, consisting of common and long rough dabs, were procured 

 at some distance from land and in deep water, As a rule, however, many 

 young fishes, such as the cod, coal-fish, whiting, and pollack, are found 

 close inshore, probably because they find their food more readily accessible, 

 and their freedom from attack greater. The same habit is characteristic 

 of the young flounders, dabs, plaice, and turbot, the very young of several 

 of these in their transparent stages being caught at the margin of the 

 rocks or in pools on the sands. It is evident, however, that from some 

 cause or other the larger plaice, turbot, halibut, and ling, generally take to 

 deep water. Indeed, in a shallow bay like that of St Andrews it not infre- 

 quently happens that the large plaice found close inshore are sickly or 

 blind. It is known that the young cod, whitings, green cod, and pollack 

 make for the deeper water in their later stages, and it is possible that a 

 similar tendency exists in the large flat fishes, especially such as the hali- 

 but and turbot. The constant presence of young ling off the beacon rocks 

 near the pier is another example of the tendency above noted. 



This year (1885) very young cod have been less numerous off the 

 tidal rocks than last year; it may be from the prevalence of cold east winds 

 in summer and autumn. On the other hand, those of a larger size (8-18 

 inches) have been more plentiful than usual, and the same may be said of 

 the young green cod (coal-fish) of the same dimensions. 



Diseases of Fishes. 



Further Remarks on the Multiple Tumours of Common Flounders, ^c. 



These tumours have been met with during the season in common flounders 

 and plaice. It was stated last year that when cut into in the fresh state 

 (in a plaice) no cells were visible in the whitish creamy fluid which exudes. 

 It is possible, however, that this depends on the condition of the specimen 

 in regard to the stage of the disease. In a large tumour projecting from 

 the mouth of a common flounder, a section presented the usual miliolai 

 appearance, and the fluid scraped from the cut surface showed masses of 



* Vide Report on Trawling by H.M. Commissioners, 1885, p. 356. table iii. 



