SEPTEMBER 8, 1899. ] 
What is urgently needed at the present 
time in comparative anatomy, especially 
that relating to the domestic animals, is a 
thorough revision in the light of this last 
half of the 19th century ; then the student, 
whether especially trained in human, veter- 
inary or comparative anatomy, could pass 
from form to form and far more easily cor- 
relate truly homologous parts, because they 
would bear the same designations ; and he 
would thus be led to see and appreciate the 
true kinship, although at first sight there 
might appear to be only unlikeness. 
If any one cannot see the force of what 
has been said, or does not feel any lack in 
the present conditions, let him think of the 
different joints in the limbs of man, horse, 
dog, chicken and honey bee ; or let him ask 
some one who knows the animals well, 
but is untrained in advanced anatomy. , I 
believe that such an experience would con- 
vince any open-minded inquirer that like 
‘designations for homologous parts are desi- 
rable; and, secondly, he would be filled 
- with increased admiration for the view of 
organic nature which points out the signifi- 
cance of a real likeness in what appeared 
in the beginning so utterly diverse. Here 
then is work which. stands ready for the 
ablest zoologists. 
In Embryology and Physiology the do- 
mestic animals have always furnished the 
greatest amount of information, as one can 
satisfy himself by consulting any treatise 
upon these subjects, although ‘ Human Em- 
bryology,’ ‘Human Physiology’ may be 
printed on the title page. Who did not get 
his start in embryology by studying the de- 
velopment of the chick, the dog, cat, rabbit 
-or guinea pig? Andin physiology students 
are almost equally dependent on the dog 
and rabbit. What is known in these fields 
is but a drop in the bucket, and as the 
-domestic animals have contributed the 
greater part of that drop, so will they be 
-called upon to fill the bucket to the brim. 
SCIENCE. 309 
And what a splendid outlook there is at the 
present time. New discoveries in physics, 
like the X-rays, make possible advances in 
physiology. Perfection of technique in 
microscopy makes advance in embryology 
possible. Contemplate the opportunity and 
the promise fora moment. There is not a 
single treatise in any language which deals 
adequately with the embryology of the 
domestic animals, and the only one in Eng- 
lish, the only one usually studied by the 
veterinary student, is hopelessly bad and 
antiquated. If one glances at the tables 
showing the zoological position of the dif- 
erent domestic animals he must be im- 
pressed with their wide distribution in the 
animal kingdom and their representative 
character. What an opportunity is here 
for work in comparative embryology! It 
is coming to be felt that the embryology 
of the present day is very inadequate in that, 
while it professedly deals with the entire 
development of the individual, it really de- 
votes its main energy to the earliest stages 
and to the very beginnings of the organs. 
The complete ontogeny of the individual 
must go further than this and trace the de- 
velopment from the ovum through all the 
life stages to old age and death. It is only 
among’ the domesticated forms, in the higher 
groups at least, that abundant material 
under complete control, is at command, 
without very great expense. Abundant 
material, with full knowledge concerning it, 
will be required for satisfactory monographs 
in the future. 
For students, material in great amount 
at a merely nominal cost, and without 
sacrificing animals especially for the pur- 
pose, may be had at every large abat- 
toir; and every village slaughter house 
wastes more than enough embryological 
material every year to supply the as- 
piring young zoologists in its precincts. 
That this material is being utilized is evi- 
dent from the admirable papers upon em- 
