THEIR MOTHER HAD FOURTEEN CALVES AT EIGHT BIRTHS 
She is a grade Guernsey, while the sire was a grade Hereford. The male calf (in the 
center) resembled his mother in color and markings, while the other two (infertile 
females or “free martins”) inherited the color and markings of their father, 
including the white face which is so characteristic of the Hereford breed. 
Photo- 
graph reproduced by courtesy of the Maine Agricultural Experiment Station. 
(Fig. 16.) 
regularly. But deliberate attempts, ex- 
tending over a series of generations, 
have rarely been made. 
EXPERIMENT OF DR. BELL 
One of the most notable experiments 
is that of Alexander Graham Bell, who 
for a quarter of a century bred his sheep 
steadily with a view to getting the 
ewes to produce more young at a birth. 
His method of procedure® was to select 
for breeding each year the ewes which 
had extra nipples, above the single pair 
regularly present. There appears to be 
an association between extra nipples and 
extra fecundity. When Dr. Bell dis- 
posed of his flock, a short time ago, he 
had built it up to a point where none of 
the ewes had less than four nipples and 
many of them six, and where twins were 
produced in a large majority of the 
births. 
Having kept a careful record of his 
flock, Dr. Bell was able to find some of 
the external conditions that seem to be 
involved in the production of twins in 
sheep. Among them are maturity of 
the mothers, mating in October, and a 
rapid increase of weight at the time of 
mating with subsequent loss of weight. 
The last-named factor was controllable, 
and he had some success in increasing 
the number of twins born, by feeding 
up the sheep just before mating, and 
letting them lose weight afterward. 
So far as is known to the writer, no 
such attempt at breeding for fecundity 
has ever been made with cattle. It 
would be a tedious and expensive under- 
taking, but if the character is really 
inheritable, one ought to be able to 
breed it into other animals, after- it 
had once been “‘fixed”’ in a given strain. 
It would therefore appear that the 
attempt to produce a family of cows 
that would yield a large proportion of 
twins and triplets, might be a practicable 
and profitable proceeding. 
5 See THE JOURNAL OF HEREDITY, Vol. V, No. 2, pp. 47-57; February, 1914. 
137 
