282 SALMONID^ OF BRITAIN. 



a depth. Neither do these fish attempt to pass up to the heads of streams for 

 breeding purposes, but select shallow localities near where they usually reside, and 

 where females may be seen waited on by two or even three males. The ova are 

 more delicate than those of the trout or char, and it has been remarked in 

 Herefordshire that shou.ld a severe frost occur during their spawning season, .the 

 succeeding year's supply of young fish appears to be deleteriously affected. The 

 body of the embryo is visible in the egg on the ninth day, and usually hatches 

 from about the twelfth to the twenty-fifth day : due to this rapid development, it 

 becomes diflBcult to transmit eyed grayling ova to any distance, as but few days 

 elapse between the appearance of the eyes of the embryo and the eggs hatching. 

 The young when hatched must be kept in very pure water, for that which is 

 sufficiently good for a trout alevin is not always suitable for grayling. At the 

 hatching time the egg-shells should be at once removed as they are found to be 

 very deleterious. About the end of July or commencement of August the fry are 

 about four or five inches long. In aquaria it has been observed that young salmon 

 or trout will readily eat young grayling. 



During the breeding season the grayling loses much of its natural timidity ; 

 thus we are told by " Southwest" in The Field, January 30th, 1886, that in the Test 

 " About eighteen brace of grayling were removed on Wednesday, and laid down 

 higher up the river, where they will probably spawn. They were conveyed to 

 their destination in a punt half -filled with water, and as a proof of how little the 

 nerves of grayling are disturbed by the somewhat rough handling they must 

 receive from netting, I may mention that one of the fish in the punt actually rose 

 at a tiny black fly that happened to appear on the water therein. I have noticed 

 this singular absence of fear on the part of grayling on another occasion. We had 

 netted out a considerable number, and placed them in an abandoned nursery, 

 through which the stream ran. Certainly not more than an hour after their 

 capture, they rose to the flies just as if nothing had happened." 



Hybrids have been raised between the grayling and the trout, thus it was 

 stated in the Journal of the French Societe d'Acclimatation (1877, p. 495), 

 that grayling eggs from the Lake of Pavia, were during the months of November 

 and December, 1872, fertilized with the milt of the salmon-trout, and hatched in 

 January, 1873, at the School of Fish-culture. The alevins grew well ; so that at 

 6 months of age they were 3| in. long ; at 22 months, 7 in. long ; at 32 months, 

 1I'4 in. in length; and at 42 months, 13'4 in. long. They were of a slate-colour, 

 with greenish reflections, having on the back very distinct, large, and irregular 

 spots and blotches on a light ground, while the abdomen was silvery. 



They bred at the age of 22 months and 5 days, when it was found that the 

 males were already exhausted, and therefore recourse was had to trout milt. On 

 November 15th, 1875, 551 very fine eggs were obtained fi-om a female 

 21 months and 15 days old ; these eggs were hatched between December 30th, 

 1876, and January 6th, 1876. The alevins were said to have grown more rapidly 

 than trout of the same age, and at 10 months they were from 3| in. to 5'9 in. in 

 length. In appearance these young difBered from the former ones by their 

 coarseness and their habits, but par marks were present. Their colours were very 

 similar to those of their hybrid mothers, being superiorly of a greenish tinge with 

 large blotches along the upper half of the body, while the abdomen was of a gray 

 slate colour, becoming ashy- white beneath ; adipose dorsal fin clear yellow. This 



* Grayling eggs -would seem to occasionally bear removing pretty well. April 3rd, 1885, at 

 Mr. Andrew's fish-culture establishment at Guildford, I was shown 100,000 grayling eggs obtained 

 the previous evening from Hampshire streams. I took twelve in a phial of water to London, and 

 the next day to Cheltenham, and only two died : their size being 0-19 of an inch in diameter. On 

 the 6th, E. Wethered, Esq., F.o.s., was good enough to offer to make daily drawings of the 

 development of the embryo under the microscope (the glass-like walls of the ova affording 

 peculiar facilities for doing so) : and for this purpose he took two in a tumbler of water to his 

 own house. The water was changed twice a day, while each ovum was daily removed to a 

 microscope cell and subsequently returned to the tumbler ; one of these hatched on April 22nd, 

 and the other on the 24th. On the 23rd those in my hatching house began to hatch, and on the 

 28th all were out but one which could be seen inside the egg slowly moving its pectoral fins back- 

 wards and forwards. By May 10th the alevins had absorbed their sacs. 



