: Colors of West Coast Mam 
ue he cae Palins to. passivity, ae D 
This katabolic condition of the male in contradi 
-anabolié state of the female, has been used by Walla 
the bright colors of male birds, and while it does not s 
that we are justified in following him to the extent of ex 
- gexual selection, a fair consideration of his arguments seems to shor 
that this excess of vitality in the male has at least furnished the 
material upon which sexual selection may act. 
And now to return to our spermophiles once more. It has been 
seen that according to one of the laws of heredity there is always 
more or less difference between the sexes. In the case in point 
this difference manifests itself, among other ways, in the tendency 
on the part of the male to be slightly darker than the female, which 
may be explained by the katabolic state of the male inducing a sur- 
plus of energy which is expended in a darker pigment. Accor- 
dingly, however dark the female may average, we may expect the 
male to maintain a tolerably constant ratio of shade to the female. 
In order to facilitate the explanation, suppose that a certain amount 
of black has been introduced and see if it can be understood how 
it could be added to. Owing to the katabolism of the male the 
ratio between the shades of the two sexes will maintain an average 
constancy. Suppose, in the evolution of the race, it has reached a | 
. point where the color is brindled, a mixture of black, brown and 
white, but in which the dark colors arein the ascendant. Some- 
thing like the following proportions of color would then exist in a : 
fairly typical pair: 
MALE, FEMALE, : 
DOWN oo i si a go op ee 10 20 
PURO by ou ee Nyack ee ieee sd en ees 60 40 
WEE os Sena ese Jee eis se ei 3 40 
According to Haeckel’ s law of mixed or mutual transmission, and 
more important still, according to many observed cases, a combina- 
tion of all the characters of the two sexes may produce an average 
between them. And it is perfectly reasonable to suppose in the 
case in point, that out of a large number of pairs possessing the 
average proportion of colors given in the table above, a few of the 
female offspring would be found to possess a medium between the 
colors of the two sexes of their parents. In these females the pro- 
portion of colors would be about as follows: Brown 15, black 50, 
and white 35. These darker females being more in 1 harmony with. . 
