Selection and Breeding 
105 
average time. During the second week the dis¬ 
charge begins to grow less and the swelling subsides 
somewhat. This is usually about the fourteenth 
or fifteenth day and this is considered the best time 
for the mating with the dog. As a rule she will 
accept him voluntarily, although it is not unusual 
for her to do this before this time or even a week 
after, or as late as the twenty-first day, hence it 
becomes obvious that she must be kept confined 
during the full period. Some breeders are of the 
opinion that sex in the puppies may be controlled 
according to the time when the mating is consum¬ 
mated, their theory being that if the bitch is bred 
early in the season, she will be prone to have more 
females; while if bred late in the season, the males 
will predominate. This, however, is a theory that 
has never been proved by indisputable data. When 
it is possible, it is best to allow the bitch to select 
her own time for service; hence, it is well for the 
owner of the bitch to send her to the owner of the 
stud dog in ample time and if the stud dog owner 
takes a real interest, he will use his discretion in 
the matter. Sometimes it happens, and especially 
with maiden bitches, that they will not take the 
dog voluntarily at any time, in which event they 
must be held and forced. Such forced services are 
usually as productive as the voluntary ones if the 
copulation occurs at the proper time. It is also 
possible that some bitches cannot mate with the dog- 
under any circumstances, due to some functional 
disarrangement on the part of the bitch. Frequently 
the use of the dilator is necessary, but unless the 
breeder is experienced in such matters, it is well 
