466 ME. F. DAY ON THE BREEDING OF SALMON FROM PARENTS 



several (? 6) years of age bad a head of a longer proportion * than is seen in these fishes 

 kept under normal conditions. In short the fish was not well grown — there had been an 

 arrest of growth due to its various surroundings. At the same time I received from 

 Mr. F. Buckland four examples of undoubted Salmo salar, reared by him from eggs 

 received from Huningen, and which were collected from Salmon captured fortius purpose 

 from below the falls of Schaffhausenf . As year after year passed by and these fish were 

 still retained in the comparatively small amount of fresh water which sufficed to fill the 

 tanks in the Horticultural Gardens, they became lanky and apparently half-starved fishes, 

 similar to those which have been descrihed by Dr. Murie (I. c, and in his 2nd paper 

 P. Z. S. 1870, pp. 30-50, " Irregularity in the Growth of Salmon"). 



Can Salmon be reared in small pieces of water or ponds through which a good current 

 of water is kept flowing and wherein there is a sufficiency and variety of suitable food? 

 To this we have a reply from Howietoun, to which I shall presently allude, that Salmon 

 can be so kept and reared, but the size to which they will yet attain time only 

 can demonstrate. 



Certain hybrid Salmon have been reared and kept for some years in the Howietoun 

 ponds: so far most have proved to be sterile, and the size to which they have attained 

 lias been unsatisfactory ; but the fish have all been well formed and not shown that kelt- 

 like appearance usually deemed so characteristic of Salmon retained in fresh water. 

 The experiments have been as follows : — 



On November 25th, 1879, some eggs from the Lochleven Trout were fertilized from the 

 milt of the Salmon. Although many hatched, up to this period none have been found 

 fertile; the largest I have seen was on November 11th, 1881, and it was lGi inches in 

 length. They were kept in the island pond (which is 210x90 feet and from 10 to 11 feet 

 deep in the centre). On November 28th, 1883, these fish were removed to pond No. 11, 

 where they now remain. On December 21th, 1881, some Lochleven-Trout eggs were 

 similarly fertilized with Salmon milt, and they hatched March 9th, 1882. The young 

 fish were kept in a planked pond, 20 feet long by 5 feet wide, until March 13th, 1881, when 

 they were removed to the octagon pond at Craigend %, and the largest taken has been 

 10 inches long. 



It seems to me that at Howietoun those hybrid Salmon raised under the same con- 

 ditions as some Salmo salar do not augment in size so rapidly as these latter fish ; thus 

 among the hybrids between the Lochleven Trout and Salmon hatched in March 1S82, in 

 November 18S3 the largest was a little over 7 inches long, while the young Salmo salar 

 in the next pond, a year older, were from 4 to 13| inches long. If future observations 

 shall give the same results it will be necessary to ascertain whether this arrest of growth 

 is due to hybridization (which is unlikely), paucity of space or of water supply, character 

 of the ponds, or has any connection with the food. 



* Day, British and Irish Fish. ii. p. 110, pi. cxx. fig. 2. 

 t Journ. Linn. Soc, Zoology, xvi. 1SS2, p. 397. 



t These fish hegan to show symptoms of commencing fertility in May 1SS5 ; and on July 4th, owing to the stream 

 giving out due to the hot weather, all but one died. 





