440 Dr. Davy on the Temperature, %c., of Birds. [1865. 



" Some Observations on Birds, chiefly relating to their Temperature, 

 with Supplementary additions on their Bones." By JOHN DAVY, 

 M.D., F.R.S., &c. Received May 26, 1865 *. 

 The observations which I have now the honour to submit to the Royal 

 Society, have been made with the hope of contributing something to the 

 elucidation of the high temperature for which birds as a class are remark- 

 able. 



I. Of the Temperature of the Common Fowl (Gallus domesticus). 

 Mr. Hunter, in his paper entitled " Of the Heat, &c. of Animals and 

 Vegetables," published in the Philosophical Transactions for 1778, states 

 that he found the temperature of the common fowl, both male and female, 

 in the intestinum rectum between 103 and 104 of Fahr. From such ob- 

 servations as I have made, both in Ceylon and in England, it would appear 

 that the temperature of this bird is considerably higher. In the former I 

 found it as high in recto as 110 and 1 1 1, and this in December, when the 

 average temperature of the atmosphere, in that part of the island where the 

 trials were made, is about 77, which was the temperature of the air at the 

 very time. In the latter I have found it to vary from 107 to 109 *. That 

 the temperature of the common fowl should be a little lower in England 

 than in Ceylon, is no more than might be expected, from the analogy of 

 the difference of temperature of man in the two climates ; and, in accord- 

 ance, in the fowl I have found that even in England there is a slight differ- 

 ence in favour of the warmest months, comparing the results then obtained 

 with those in the coldest. 



Of the want of agreement between Mr. Hunter's results and mine I can 

 offer no satisfactory explanation. I have thought it right to advert to them, 

 he being so deservedly a high authority in physiology. Were his results to 

 be depended on, then, were the common fowl to be considered as a fair ex- 

 ample of the temperature of birds generally, they could hardly be consi- 

 dered as a class peculiar for highness of temperature, some of the mammalia 

 having a temperature differing but little from that which he assigns to the 

 common fowl f. Or, if not a fair example, then an exception, and the 



* Bead June 15, 1865. See Abstract, page 337. 



f* The trials from which the last-mentioned results were obtained Jiave been made 

 during the last two or three years, using a delicate thermometer of Negretti and Zambra 

 made for the purpose, which had been compared with a standard instrument. The 

 fowls tried were all barn-door fowls, living at large, and having the run of a field. The 

 number of females examined was 37, of males 25. The mean temperature of the former 

 in recto was 107'64 ; the highest 109, the lowest 107 ; of the latter the mean tempe- 

 rature was 108-25, the highest 109, the lowest 107. 



| In Ceylon I found the temperature of the blood of the wild hog, as it flowed from 

 the divided great cervical vessels, 106, and that of the pig in Engknd, in two instances, 

 of the same degree ; both were in excellent condition, and were killed in December ; of 

 one the temperature of the blood was tried ; of the other, the cavity of the abdomen. 

 The temperature of the sheep I have found to vary from 103 to 105 in recto ; the 

 latter in Ceylon. 



