18 Proceedings of the Royal Physical Society. 
American, we cannot expect to arrive at any correct result, 
until we have the means of making a more complete compara- 
tive examination than has yet been done of the two species 
alongside of each other. Notwithstanding the greater dis- 
tance of its locality, we possess both better materials and 
more accurate information on scientific points regarding the 
species from North America than that from Lapland. It 
is to the latter that our inquiries should now be directed, and 
more accurate information sought for on such points as the 
periods of growth and shedding of the horns, referred to in 
my previous communication, and in Mr Mackenzie's letter. 
His statements on this point have been confirmed to me by 
Mr Hargrave, who also informs me, that the head with distorted 
horns, sent last year, which was figured in the first part of this 
paper, was that of a young animal, not more than two years old. 
He mentions, that a slight bend is common in the first year ; 
that this becomes of the distorted form above referred to in the 
second year, but afterwards disappears. I was misled, by the 
teeth being much worn, into the supposition that it was an old 
animal. These worn teeth must be the milk teeth ; and we 
thus have incidental information as to the period the animal ^ 
carries them. 
Information on such points becomes of importance, because 
the North American and Lapland species are so closely allied 
to each other, that we cannot expect to find distinctions of a 
prominent nature, and must be content with the accumulation 
of those of a more subordinate character. I may notice, that 
I find the view which I adopted — viz., that the species are dis- 
tinct — has also been entertained by Professor Spencer Baird 
of America, who, in his recent *' General Report upon the 
Zoology of the several Pacific Eailroad Eoutes, Part I. — 
Mammal," includes two species of rein-deer as inhabiting the 
northern shores of North America (the Rangifer caribou and 
R, Grcenlandicus), and both distinct from the Lapland deer; at 
the same time admitting that their distinctness is questionable. 
Moosr: Deer (Cervus Alces, Lin.). — Mr Hargrave has had 
the kindness to send me a magnificent head and horns of this 
fine elk, which is another animal as to whose identity with its 
