158 Mr. Home’s Account of the 
This compound animal attracted the attention of the late Mr. 
Hunter ; and a Paper of his, containing a description of the 
organs of generation of different free-martins, to shew that they 
are by no means uniformly the same, or partake equally of the 
parts belonging to both sexes, is published in the Philosophical 
Transactions, Vol. LXIX. To add to these dissections an ac- 
count of similar formation of the organs of generation in a dog, 
is the intention of the present Paper. The subject having already 
been considered an object deserving the attention of this learned 
Society, is an inducement for bringing forward new facts, and 
observations which have been made respecting them. 
The causes of monstrous productions of every kind are at 
present equally unknown, but it is highly probable that they are 
very similar; and, when once they have been brought into 
action, it would be reasonable to suppose, that the influence 
should be continued to several young, in succession; this is, 
however, by no means the case, for, of all the monstrous pro- 
ductions that have come under my observation, none of them 
have been either immediately preceded, or followed, by a mon- 
ster of the same, or of any other kind. 
In the neat cattle, the free-martin is most commonly met 
with where there are twins ; one is a free-martin, and the other 
is always a perfectly formed male. In the human species, there 
have been instances of mothers having alternately a perfect and 
a monstrous child ; so that these observations lead to the idea, 
that monstrous productions do not follow immediately upon one 
another ; that they sometimes alternate ; but are commonly, as 
in the child with the double head,' (an account of which has 
been laid before this Society,) only one in a family, of which 
the others are perfectly formed. 
