364 Ewarr— Variation: Germinal and Environmental. 
not in season, the buck served her, with the result that she had two young forty 
days afterwards, z.c. onthe 20th July. I proved subsequently that this doe carries 
her young thirty days, which means that, though she was served on the 10th of 
June, ovulation only occurred ten days later, on the 20th June, and this of course 
imphes that, in the rabbit, spermatozoa may retain their fertilizing power for at 
least ten days after they reach the fallopian tube. ‘The two young rabbits were 
pure white, and when they grew up they readily passed for hali-bred Angoras. 
The three grey sisters of this doe only reached maturity during their sixteenth 
week, from which it may perhaps be inferred that the presence of the sperms in 
the oviduct induced premature ovulation in the dam of the two white half Angoras. 
A few hours after the two white young were born I put their dam, the grey doe, 
to a grey buck, a descendant of two half-wild rabbits. Thirty days afterwards 
(on the 19th August) she had ten young—five grey, two bluish-grey, and 
three white. 
Ovulation does not seem to occur in the rabbit before the act of insemination, 
but it is generally said that the doe refuses to take the buck for some weeks unless 
presented to him during the first, second, or third day after parturition. I have, 
however, several does that have been successfully served from nine to eighteen 
days after the birth of their young. 
Instead of serving the grey doe on the 19th August—the day she had her ten 
young—lI postponed the service until the 6th September, z.c. eighteen days beyond 
the usual time. This time I again used the Angora buck, with the result that on 
the night of the 6th October the doe had four young, all of which were in every 
respect identical with new-born, half-wild and wild rabbits. To make what follows 
clear, I may here explain that, about a week or ten days before the young arrive, 
the female rabbit (tame as well as wild, when the circumstances permit) excavates 
a nest nearly at right angles to the main burrow, lines it with grass or hay, and 
then carefully closes up the opening with sand or, in the case of tame rabbits, with 
whatever material may be available—the nest is doubtless made thus early to give 
the grass lining time to dry. Two or three days before the young are born the 
nest is re-entered and provided with an inner lining of hair which the doe very 
cleverly tears off her breast and sides. Finally, as the young are one by one born, 
the foetal robes are, with wonderful dispatch, torn asunder and devoured along 
with the placenta. After the all but hairless young have been well licked—which 
warms them as well as cleans them—they are arranged in a clump and roofed over 
with a light covering of hair: this covering is dispensed with when the hair of 
the young is sufficiently developed. 
The grey doe served on the 6th September made no preparations whatever for 
the young born during the night of the 6th October. On the morning of the 7th 
October, one was already dead, the other three were sprawling about in a 
