ZOOLOGICAL EEOORD 
FOR 1871. 
MAMMALIA 
BY 
Albert Gunther, M.A., M.D., Ph.D., E.R.S. 
The General Subject. 
a. Beparaie Publications. 
Darwin, C. The Descent of Man, and Selection in relation to 
Sex. London : 1871. 16mo, voL i. pp. 423, vol. ii. pp. 475, 
illustrated by numerous woodcuts. 
As is indicated by the title, this work consists of two parts, 
the second of which comes within the scope of the ^ Zoological 
Record;^ and here we have particularly to refer to chapters 17 
and 18, in which the secondary sexual characters of Mammals 
are discussed. The main theory of sexual selection depends 
upon the fact that there is a struggle among the males for the 
possession of the females — a struggle carried on either by actual 
lighting or by rivalry in various charms, as odour, voice, or 
beauty. Among Mammalia the law of battle appears to prevail 
throughout ; and the greater size, strength, courage, and pug- 
nacitjr of the male, his special weapons of offence, as well as his 
special means of defence, have all been acquired or modified 
through sexual selection. Likewise the odoriferous glands and 
the ornamentations of the integuments have been developed in 
the male through the same cause ; but whether, in Mammals, the 
same view can be extended to the voice, is doubtful. The law 
of the equal transmission of characters to both sexes, as far as 
1871. [vol. VIII.] B 
