564 
The correlation of cestrus and lacta- 
tion with fecundity has been carefully 
studied by the writer during thirty-five 
years experience in breeding horses. 
Indubitable evidence has been found 
that mares above the average in 
fecundity have a prolonged cestrum 
and highly developed mammary glands. 
This mare had the first cestrum when 
eight months old, which lasted six days 
and has never been of shorter duration 
but has sometimes lasted ten days. 
The mammary glands are so highly 
developed that 1 gallon of milk has been 
taken from her when weaning a foal. 
These characters have been transmitted 
to her daughter and by her to the grand- 
daughters. 
INFLUENCE OF ENVIRONMENT 
Without entering into a discussion 
of the effect of environment upon the 
The Journal of Heredity 
germ cell, we may say that the fullest 
expression of fecundity in this case is 
due in a great measure to environment. 
She has been given a wide range on blue 
grass land, underlaid by Trenton lime- 
stone, and fed upon grains produced by 
the same lands, so rich in phosphates. 
She has never been permitted to become 
thin in flesh and has had a roomy, well- 
ventilated box in winter. Her teeth 
have been dressed once each year and 
when foaling she has had the same care 
that would be given a mother in a 
maternity hospital. A practical experi- 
ence of many years aided by dissection 
of subjects of various ages and physical 
condition has convinced the writer that 
the 40% of all mares bred that fail to 
produce foals can be materially reduced 
by impressing upon breeders the effect 
of environment upon the germ cell. 
ALL BREEDERS SHOULD KEEP RECORDS 
The unusual record of Mantua Maker 
as a producer carries a valuable lesson 
for all livestock breeders. A mare 
which can fulfil her obligation to 
posterity year by year as this mare has 
done, and at the same time keep the 
good health and sweet, benign disposi- 
tion which her photograph shows, de- 
serves something of the same respectful 
homage which all true men pay to the 
noble human mother surrounded by a 
troop of sturdy sons and daughters. 
Livestock breeders will do well to 
hold the producing females as long as 
they produce. Fecundity is unques- 
tionably inherited, and while it is not 
manifested so emphatically in the case 
of mares as in other farm animals, it is 
one of the powerful factors which the 
breeder has at his command. Simple 
produce records can be kept by every 
farmer and breeder, and will soon show 
which are the best producing individuals 
and which the most productive strains 
in the herd. By weeding out the non- 
producers, the factor of fecundity can 
be increased in the herd and its efficiency 
greatly augmented. 
It would be interesting to know of 
other cases of high productiveness like 
that of Mantua Maker. 
Geo. M. RoMMEL, 
Secretary, American Genetic Association. 
The Transmission of Rabies 
Under the misleading title of ‘“‘Studies 
on the Heredity of Rabies,’’ Daniel 
Konradi describes in the Annales de 
l'Institut Pasteur, XXX, 33-48, his 
researches at the Institute of Pathology 
and General Therapeutics at Kologsvar, 
Hungary. It appears from a summary 
in the [nternational Bulletin of Agricul- 
ture that rabies is transmitted by the 
mother to the fetus, but is attenuated 
in the process. Experiments are cited 
with dogs, rabbits and guinea-pigs; the 
latter are the most susceptible. Such a 
transmission is not inheritance, and 
much confusion has been caused in the 
study of heredity in the past, because 
of carelessness in ruling out cases of 
transmission to embryo from the mother. 
