34 
Proceedings of the Royal Society of Edinburgh. [Sess. 
In the light of these remarks it is interesting to examine the mean 
temperature for each order as shown in Table III. Here it is seen that the 
Tubinares have the lowest temperature and the Longipennes the highest. 
Arranged according to body temperature, the order from below upwards is : 
Tubinares, Steganopodes, Pygopodes, Anseres, Longipennes, while the 
.zoological series, ascending, would be Pygopodes, Longipennes, Tubinares, 
Steganopodes, Anseres. This is not in agreement with the idea held by 
Sutherland. In the mammalia, above the marsupials and monotremes, it is 
a well-known fact that this law does not hold good ; there is no parallelism 
between the body temperature of an animal and its anatomical position, for 
in the temperature scale Homo sapiens, with one exception — the ass — 
occupies the lowest place, while in the zoological scale he is the highest. 
The same appears to be the case amongst the class Aves, above the Ratitse. 
It is true that only one specimen of the Tubinares was examined — the 
storm petrel — and it would be rash to give the number obtained from a 
single observation as the mean temperature of the whole order, were it not 
for the fact that this figure agrees closely with that found by previous 
observers. Eydoux and Souleyet * give 40 o, 7, 39 0# 6, and 39°‘7 as the mean 
temperatures of three species of the petrel family, and the mean of five 
observations by Martins j- on as many individuals of another species ( Procel - 
laria glacialis ) is lower still, viz. 38°'76. There seems to be no doubt, then, 
that amongst the web-footed birds the Tubinares, or rather the family 
Procellariidse of this order, have the lowest temperature. 
Even families of the same order appear to differ considerably in body 
temperature. In the Steganopodes the Sulidse (gannets) have a mean 
temperature of 41°’44 C-, while for the members of the Phalacrocoracidse 
which were examined (cormorant and shag) it is much lower, viz., 40 o, 07 C. 
The comparison here, however, is hardly fair, since in the gannet the ob- 
servations were made on birds that were alive, although they remained 
quiet throughout the whole operation, while in the cormorant and shag the 
temperature was taken immediately after death, and it may be that this 
would account for the difference. 
In order to find how the temperature of the wild duck compares with 
that of the domesticated variety, I obtained access to a small flock of 
mallards kept in a pen at the New York State Agricultural College, 
Cornell University. The colony consisted of three drakes and six ducks, 
from one to two years old. They were three generations from the wild 
form, and could be handled easily. The observations recorded below were 
made on April 5, 1909, between 2 and 3 p.m., with the air temperature 
* Eydoux and Souleyet, loc. cit. + Martins, loc. cit. 
