i9iC Scientific Itttdligence. — Zuologr/i- 



our breathing became more and more oppressed ; fainting,, sick- 

 ness, giddiness, and bleeding at the nose came on ; and, in this- 

 condition, we lay a considerable time, until the symptoms grew- 

 milder from repose, and we were able to descend slowly. 



12. Temperature of' Fishes. — DrDavy, in a paper read before 

 the Royal Society of London,^ stated that he bad occasion to ob- 

 serve, many years ago, that the bonito ( Thynnus pelamys ) had 

 a temperature of OQ"" of Fahr., when the surrounding medium 

 was 80°5, and that it, therefore, constituted an exception to the 

 generally received rule that fishes are universally cold-blooded. 

 Having found that the gills of the common thunny of the Me- 

 diteranean Sea (Tkynmis vulgaris, CuvJ were supplied with 

 nerves of unusual magnitude, that the heart of this latter fish 

 was very powerful, and that its muscles were of a dark colour, 

 he was led to conjecture that it might, like the bonito, be also 

 warm-blooded, and this opinion is corroborated by the testimony 

 of several intelligent fishermen. The author endeavours to ex- 

 tend this analogy to other species of the same family, which, ac- 

 cording to the reports of the fishermen of whom he made en- 

 quiries, have a high temperature, and in whose internal struc- 

 ture he noticed similar peculiarities, as in the thunny ; namely, 

 very large branchial nerves, furnished with ganglia of considerable 

 size. In this respect, he considers that in these fishes the bran- 

 chial system of organs make an approximation to the respiratory 

 apparatus of the mammalia, and that it probably contributes to 

 the elevation of temperature, resulting from the more energetic 

 respiration which he supposes to be exercised by these organs. 

 He, however, thinks it not improbable that these fish may pos- 

 sess means of generating heat peculiar to themselves, and of 

 which at present we have no adequate idea. He conceived that 

 the situation of the kidneys, of which a considerable portion is 

 even higher than the stomach, and posterior to the gills, and 

 which are of large size, and well supplied with nerves and bloods 

 vessels, may possibly act a part in the production of an elevated 

 temperature; but, on the whole, he is disposed to ascribe the 

 greatest share of this effect to the superior magnitude of the 

 branchial nerves. 



i3. Salmon of the Columbia River. — Dr Gairdner, in a let- 

 ter, dated Fort Vancouver, November 1834, says: — " I have 



