Zoology. 537 
nocturnal habit. It is quite in keeping with the habit of many of 
the order; and the vertical pupil of the eye points likewise to the 
same fact. This, however, in itself, must be a comparatively small 
factor in the case, and, alone, would hardly insure it against frequent 
detection any more than does a similar habit in many other noctur- 
nal animals. I had gone by this hollow repeatedly, night after 
night, both before and after this appearance, and, though constantly 
on the alert to notice anything of the sort, had no hint of their 
presence. 
Doubtless, the solitary burrowing habit goes much further in 
explaining its seclusion. But even this would be inadequate, unless 
the animal persistently avoided all open and cultivated grounds. 
age only, would protect it against frequent exposure by the spade 
or plow. 
Altogether, they are certainly the most peculiar and erratic of 
any of the order; and, under the peculiar difficulties in the way of 
continuous study, it will be long ere its life-history can be said to 
be thoroughly known. However, the very difficulties add a charm 
to the investigation, which we may hope will lead to success. To 
me, the brief research herein outlined has been full of the liveliest 
interest, and, while but a mite toward the solution of the problem, 
I shall hope that it may not be without some value when a final 
summary is made.— C. W. Hargitt, Moores Hill, Ind. 
Tae RELATIVE WEIGHT OF THE BRAIN TO THE BODY IN 
Biros. — In a former number of the AMERICAN NAT- 
URALIST,' notice was made of the relative weight of the brain 
to the body in Spizella socialis, and Regulus satrapa compared to 
that of man. Since that time more extended investigation has been 
made, with a view of ascertaining the relative weight of the brain 
to the body in different species of birds, the result of which is 
appended below. 
An interesting fact dey eloped from these figures is that there is 
considerable individual variation in the weight of the body an 
brain in different individuals of the same species ;” this is no doubt 
ependent in some way upon the time of year, the amount of food 
supply, and individual idiosyneracy ;° there is no sexual distinction 
1m regard to the relative weight of the brain to the body—but, on 
the contrary, male and female alike offer marked degrees of fluctu- 
ation in this regard. Exception, however, exists in the two speci- 
mens of different sexes of _Harporhynchus rufus, which closely coin- 
cide in their relative weights. 
ost of the specimens considered here were taken at Grand 
Crossing, Illinois, the remaining ones in Chicago. Light loads of 
Abas xxi., April, 1887, p. 389. 
aN’ especially the series of weights of Dendroica wstiva. — 
weighed nt specimen of Dendroica estiva, taken June 4th, which 
ore in body and brain than any specimens of the —— 
cies taken before nar date. © 
