74 The American Naturalist. [January, 
others of a naturally uncertain course, nearly if not always elude the 
bird’s bill. 
He also reports that the sparrow is very fond of picking up the in- 
sects injured or killed by the electric lights.—F. C. K. 
The Origin of the Chiropterygium.—lIt has been said that the- 
limb of the higher Vertebrates—Man, Reptile, Batrachian—does not 
exhibit the rayed structure of fishes. To explain this condition M. 
Mollier offers four possible solutions. 
1. A single ray may have persisted and present segmentation is a. 
secondary formation, all the other rays having degenerated. 
2. Two rays only may have been preserved. Traces of these two rays. 
would then be found in the forearm. The five fingers would be a 
secondary division, while a fusion of two rays would take place in the 
region of the humerus. 
3. Five primitive segments might be represented, indicated both by 
the number of nerves together with the muscular buds, and by the 
number of the fingers. 
4, The number of rays might be indefinite; they united to form a 
single mass, which ulteriorly underwent a secondary segmentation. 
To the first hypothesis is opposed the fact that concentration is every- 
where the rule, while this supposition would necessitate that the primi- 
tive outline, which had started from at least two segments, must en- 
large. 
As to the second hypothesis, embryology shows that the two bones of 
the fore arm develop from a single mass. 
The third hypothesis rests on several concurrent conditions. But 
we find, according to M. Mollier, that the number five is not constant. 
Among the Batrachians, there are only three. 
The only plausible theory then, is the fourth which agrees with all 
the facts of embryology which Mollier therefor accepts. (Revue 
Scientif. Sept., 1895, p. 340.) 
A New White-footed Mouse from British Columbia.— 
During a collection trip in the northwest, Mr. Will C. Colt made sev- 
eral excursions to Saturna Island (in the Gulf of Georgia half-way 
between Victoria and Vancouver City), British Columbia, and secured 
there over two hundred white-footed mice. This enormous series, now 
in the Bangs collection, taken in January, February, March, April and 
May, 1894, represents a strongly marked and hitherto undescribed 
subspecies of Peromyscus texanus. The same form is probably found 
on all the islands and coasts of this vicinity, and agrees in its dark 
coloration with the whole fauna of this saturated region. 
