INTRODUCTION. 85 
sive generations, of looking forwards to their master 
and obeying his voice.” 
This extract, taken from the Penny Cyclopedia, 
where it appears as a quotation, is then followed up 
by a paragraph not clearly pointed out as being in 
continuation, though the diction seems to be that of 
the same writer; it is as follows :—“ Another crite- 
rion, and a sound one, is the identity of gestation. 
Sixty-three days forms the period during which the 
bitch goes with young; precisely the same time 
elapses before the wolf gives birth to her offspring. 
Upon Buffon’s instance of seventy-three days, or 
rather the possibility of such a duration in the ges- 
tation of a particular she-wolf, we do not lay much 
stress, when opposed to such strong evidence of the 
usual period being sixty-three days; the young of 
both wolf and dog are born blind, and at the same 
or about the same time, viz. at the expiration of the 
tenth or twelfth day. Hunter's important experi- 
ments proved without doubt that the wolf and the 
jackal would breed with the dog, but he had not 
sufficient data for coming to the conclusion that all 
three were identical as species. In the course of 
those experiments he ascertained that the jackal 
went fifty-nine days with young, whilst the wolf 
went sixty-three ; nor does he record that the pro- 
geny and the dog would breed together; and he 
‘knew too well the value of the argument to be 
drawn from a fertile progeny, not to have dwelt 
upon the fact, if he had proved it; not to have 
mentioned it, at least, if he had even heard it.” 
