jSSg.J Zoology. AA9 
the above : "We have seen several of these 'mule-footed'' 
hogs. In a small Southern town, a large Poland-China boar 
had one hind foot exactly like the one shown in our picture, 
and a large proportion of the young pigs from him were 
marked in the same way." 
We have also had undoubted cases of extra-toed horses 
reported here. During the summer of 1885, The Advertiser, 
Constantine, this State, contained the following : " On Wed- 
nesday night of last week a mare belonging to Mr. Fred 
Hagenbuch, of Fabius, gave birth to a male colt, well formed 
and perfectly symmetrical in all respects, except that one of 
the feet is cloven and hoofed like the foot of a cow. Who has 
a rnate for this colt >" This was quoted in Breeder s Gazette, 
Chicago, the leading breeder's paper of America, and brought 
out a response from Mr. N. C. Woolf, in issue for July i6th, 
thus: "My neighbor. Mr. D. M. Hall, has a two-year-old 
colt that exactly fills the above description. For a few 
months Mr. Hall has taken great pains in shoeing, and thinks 
he will succeed in making a pretty good hoof." 
These cases are, I think, of sufficient interest to entitle 
them to be rescued from the oblivion that they must experi- 
ence. And they are, I think, of sufficient value to have a 
place accorded them in The Naturalist. — i?. C Aidd,. 
Pinckney, Michigan, U. S. A. 
Interesting Cases of Color Variation— As a contri- 
bution to the increased interest attaching to the recent discus- 
sions of color variation in animals, as bearing upon the problems 
of natural selection, the following may not be without value, 
^he first is that of some remarkable variations in color in the 
common robin, Merula migratoria. Some two years ago, in 
the Spring of 1887, while studying the habits of this bird, 
strolling almost daily into their haunts, I was much struck by 
what at first appeared a strange bird among a group of 
robms. A moment's attention, however, disclosed the true 
character of the stranger, and showed it to be strange only in 
the matter of color, which was a motley of white and gray on 
the head, neck, shoulders and back. Though having no means 
of securing the specimen at the time, an attentive study of the 
marking showed that it could not be a case of albinism, as 
IS so often the case in such variations. The bird was not seen 
or that time only, but I saw the same specimen a i^^ days 
later, and then repeatedly during the Spring, as it proved to be 
a female, and nested near my home. No propagation of the 
variation appeared in the offspring that was appreciable. 
