VOL. It. | ‘atural History of the Farallones. 159 
ers have well-defined ideas of individual rights and the impropriety _ 
of ‘‘jumping claims.’’ Mr. Walter E. Bryant, in his Birds and 
Eggs from the Farallon Islands,* suggests that the curiously pro- 
nounced pear shape of the guillemot’s egg is ‘‘an all-wise provision 
* * > preventing it from rolling off of a slightly inclined plane ”— 
by which he means, I suppose, that it has been brought about by 
natural selection. This is a very interesting observation regarding 
the significance of the shape of the egg, and certainly seems to be 
perfectly plausible. The color of the guillemot’s egg is no less re- 
markable than the. shape. No- two individuals lay eggs exactly 
alike; in fact, there is probably no bird which displays so great a 
diversity with respect to color and markings as the guillemot. Still 
more interesting: one of the eggers, a man of intelligence and 
veracity, apparently, informed me that the same pair of birds always 
laid the same style of an egg. He said that on particular isolated 
ledges where only a single pair built he would invariably find one 
form of marking upon the egg. Thus, on taking the egg from 
some known spot on alternate days, he would observe it was invari- 
ably scrawled, or from some other nook constantly unmarked white, 
while a third'cranny would yield an egg spotted in a particular 
way. If this observation be frue it is of considerable interest, and 
may perhaps furnish a clue to the reason for the diversity of type 
in the eggs. With most birds the color of the egg varies but little 
from the type of the species, and we may accordingly infer that the 
particular color is of some use, and is preserved by natural selection. 
The form of the egg is frequently more variable than the color, but 
with the guillemot the reverse is the case. The shape is remarkably 
constant, and there seems to be a good reason why it should be so. 
But there appears to be an equally good reason why the color 
should be variable. In nesting in great numbers close together 
there might frequently be difficulty in keeping each pair's property 
distinct if all the eggs were alike, but this difficulty would be entirely 
obviated if each pair laid a different style of egg. Natural selec- 
tion, then, would not tend to preserve any one type of marking, 
but would rather encourage as great diversity as possible. Ifa 
pair does always lay the same style of egg the birds would learn | 
their own kind once for all. This would be especially useful if the 
* Proc, Cal. Acad. Sci. 2d Ser. Vol. I, p. 35- 
