HYBRIDS— STRUAN RACE. 265 



> 

 Scotch chav ; the deaths among the incubating eggs were, in December 138, 

 January 787, February 19-4 — or a total of 1119 ; they hatched on February 16th. 

 March 13th, 188i, upwards of 100 were present. On April 24th, 1885, they were 

 shifted to pond 5, along with similar hybrids. 



Struan Hybrids crossed. 



Day, Proc. Zool. Soc. 1885, p. 243. 



November 12th, 1884. — A female struan hybrid, twenty-one months old, gave 146 

 eggs, which were milted from a male of the same breed. Only six hatched on 

 February 3rd, 1885, or in 84 days. 



Struan Hybrids crossed. 



November 24th and 25th, 1885. — About 17,500 eggs were obtained from struan 

 hybrid.s, and crossed by males from the same breed, they being at that time thirtj^- 

 three months old. The mortality from the two lots was, in November 5735, 

 Janiiary 5635, and February 393; 1054 were unimpregnated. They commenced 

 hatching February 11th, and about 2000 young came out. Many were very weak, 

 and the mortality became considerable. July 30th, 689 fish were shifted to 20 feet 

 pond no. 3 ; and on December 27th 450 were moved to the botanical pond, which 

 is about four feet deep. About the middle of June, 1887, and the subsequent three 

 weeks when the weather was scorching and the glare great, many were observed to 

 commence to lose their coloui', to become somewhat similar to albinos, with the 

 pectoral, ventral, and anal still showing the red colour. On a net being placed 

 near them they did not move unless touched, and on being taken out of the pond 

 wei-e found to be blind : in those slightly affected in colour the pupil was fixed and 

 the colour dull, almost opaque, in those fully affected it was quite opaque. At the 

 commencement of July some wood was placed over the inlet end of the pond under 

 which the fish crowded, but the temperature of the water did not fall until some 

 rain fell on the 5th and 7th, when the fish seenied more lively. Some boards were 

 now placed over a portion of the pond for the char to get under, but no other 

 locality was available in which to transfer them. This instance is interesting, as 

 showing how excess of light and heat, added to insufficient depth of water, causes 

 mortality among these fishes. 



Struan Hybrids crossed. 



November 5th, 1886. — Twenty thousand eggs of this form of hybrid, 45 months 

 old, were milted from males of the same race, the mortality being, in November 6895, 

 December 4397, January 1503. This cross was repeated next day with 6000 eggs, 

 and the mortality among them was, November 2526, December 1257, January 657, 

 and 675 were not impregnated. They commenced hatching January 13th, and 

 continued doing so for several days. Some of these hybrid parents were two 

 years old, others a season older. As a rule, to which tliei'e were exceptions, these 

 fish were weak. On June 14th, 1887, 1250 were placed in box 4, and 1000 in box 

 no. 5 in the hatching-house. 



Struan Hybrids breeding. 



December 6th, 1884. — Six hundred ova were obtained from a 22 months old struan 

 hybrid. These ova had an average diameter 015 inch, and were milted from 

 another struan hybrid and placed in box 104&. February 23rd, or in 79 days, 50 

 hatched and were transferred to box no. 92, but only one lived, and it was placed 

 in pond 3. 



