298 ADDITIONAL NOTES. 



cious than the female, and is capable of exercising the generative 

 function long before the attainment of full growth, even as early 

 as its fourth month, and of exercising it with effect, like the 

 parr, on the ova of its parent, when next needed. (See a paper 

 communicated by me on the early generative power of the kid, in 

 the "Proceedings of the Zoological Society," for May, 1847.) 



That the parr, before the facts referred to were brought to 

 light, should have been considered a distinct species, is not to 

 be wondered at, especially taking into account that there are 

 other differences (comparing the parr and the smolt) besides 

 those already mentioned, as the situation of the fins, and the 

 form of body and its proportions. In the smolt, the dorsal fin 

 is nearer the head than in the parr, and is comparatively larger 

 than that of the parr, whilst its general form is more delicate 

 and elongated ; but how small are these differences by the side 

 of the greater which we witness in the young of so many other 

 animals during their period of growth, and which, no doubt, had 

 they been examined under circumstances like those under which 

 the parr was first noticed, might have given them claim, however 

 false, to be ranked as species distinct adult species. J. D. 



(Queries relative to the Natural History of the Trout, page 64.) 



The early history of the common trout in minute and exact 

 detail is yet a desideratum. Precise observations on its breeding- 

 period, on the development of its ova, and the rate of growth of 

 the young fish, like those made by Mr. Shaw and Mr. Yourg on 

 the salmon, are needed, and would be especially useful in rela- 

 tion to the stocking and preserving of trout-streams, and the fair 

 sport of the angler. Were such observations made on fish, under 

 different circumstances, as to temperature of water, quality and 

 quantity of food, their value would be greatly increased. The 

 tvidest limit of the spawning season of the trout, in the same 

 river, and whether it varies materially in different rivers, remain 

 yet to be determined; and also whether it breeds, as Bloch asserts, 

 every year, or, more commonly, every second year, and also at 

 what age it has the power of propagating. That its spawning 

 season extends over several months, is certain; and also, that in 

 most of our rivers it begins in September, is at its height in the 

 latter end of October and beginning of November, and does not 



