INCUBATION 
good results, however, with one male to 20 hens. In the Little 
Compton and South Shore districts, one male is used for thirty 
or even forty hens. 
By infertile eggs is meant eggs in which the sperm cell has 
never united with the ovum. Such eggs may occur in a flock 
from the absence of the male, from his disinclination or physi- 
cal inability to serve the hens, from the weakness or lack of 
vitality in the sperm cells, from his neglect of a particular 
hen, from lifelessness, or lack cf vitality in the ovule, or from 
chance misses, by which some eggs fail to be reached by the 
sperm cells. : 
In practice, lack of sexual inclination in a vigorous looking 
rooster is very rare indeed. The more likely explanation is 
that he neglects some hens, or that the eggs are fertilized, 
but the germs die before incubation begins, or in the early 
stages of that process. The former trouble may be avoided 
by having a relay of roosters and shutting each one up part 
of the time. The latter difficulty will be diminished by setting 
the egg as fresh as possible, meanwhile storing them in a cool 
place. The other factors to be considered in getting fertile 
eggs, are so nearly synonymous with the problems of health 
and vitality in laying stock generally, that to discuss it here 
would be but a repetition of ideas. 
In connection with the discussion of fertile eggs, 1 want to 
point out the fact that the whole subject of fertility as dis- 
tinct from hatchability, is somewhat meaningless. The facts 
of the case are, that whatever factors in the care of the stock 
will get a large percentage fertile eggs, will also give hatcha- 
ble eggs and vice versa. This is to be explained by the fact 
that most of the unfertile eggs tested out during incubation, 
are in reality dead germs in which death has occurred before 
the chick became visible to the naked eye. Such deaths 
should usually be ascribed to poor parentage, but may be 
caused by wrong storage or incubation. Likewise, it would 
not be just to credit all deaths after chicks became visible to 
wrong incubation, although the most of the blame probably 
belongs there. 
Likewise, with brooder chicks, we must divide the credit of 
their livability in an arbitrary fashion between parentage, in- 
cubation, and care after hatching. 
By the hatchability of eggs, we then mean the percentage 
of eggs set that hatch chicks able to walk and eat. By the 
livability of chicks, we mean the percentage of chicks hatched 
that live to the age of four weeks, after which they are sub- 
15 
