590 The American Naturalist. [June, 
does not enumerate a single specimen of the Harvest Mouse. I have 
just received a second specimen from Mr. Dickinson, who sent me the 
first one, and, as this is an adult in perfect condition and fully confirms 
the peculiar characters of number one, it may form the type of the 
following diagnosis : 
Reithrodontomys humilis dickinsoni. Type ad. 9 , No. 2240, col. of 
S. N. Rhoads. Col. by W. S. Dickinson, at Willow Oak, Paseo Co., 
Florida, Apr. 6th, 1895. 
Description: Size considerably smaller than R. humilis. Color 
above, uniform plumbeous gray, almost sooty, slightly darker along 
middle of back and rump, and a faint wash of light brown on sides. 
Tail above like back ; below, grayish, like feet and under parts. Skull 
as in humilis, but distinctly smaller. 
Measurements: Total length, 118; tail vertebra, 56 ; hind foot, 15. 
Skull, total length, 183; basilar length, 13°6; length of nasals, 671 ; 
interorbital constriction, 3'1; zygomatic expansion, 9°6; length of 
mandible, 10; width of mandible, 47 mm. 
This race of the common eastern Harvest Mouse conforms to the 
peculiarities of the Floridian as contrasted with the Carolinian environ- 
ment in the same way that its allies and neighbors of the genera Sig- 
modon and Peromyscus have done, viz.,in the diminuition of brown and 
rusty colors and the acquirement of a more or less darkened shade of 
gray. 
—Samuvue. N. RHOADS. 
EMBRYOLOGY.’ 
Grafting Amphibia.—Professor G. Born has published a prelimi- 
nary notice’ of some novel experiments made upon the young tadpoles 
of various amphibia. 
In studying regenerative processes in young tadpoles he observed 
that when a tadpole was cut into two pieces, the pieces might unite 
1 Named for Mr. W. S. Dickinson of Tarpon ae Fla. in recognition of 
of his valuable services in the collecting of Florida mammals. 
E. A. Andrews, Baltimore, Md., to shen abstracts, reviews and 
preliminary notes ma: . 
2? Jahresbericht d. Schlesischen Gesell. f. vat. Cultur Sitz., June 8, 1894. 
