308 
Association in 1877, and the address of Os- 
born before this section in 1893, know well 
the story. Starting with the generalized, 
five-toed forms of the basal Eocene in our 
own country, passing through many modifi- 
cations and lateral experiments as they may 
be called, the five-toed form gradually be- 
came the four, three, and finally the one-toed 
modern horse, with its allies, the ass and 
the zebra. ‘Thus long before the Coast 
Range was brought forth, while still the 
eternal hills were young, the primitive 
horses disported themselves in vast multi- 
tudes in our Western Territories ; and it is 
believed that from this contient they passed 
to Asia, Africa and Europe, only to come 
back in these latter days to this so-called 
New World after making the circuit of the 
entire earth. 
Among living forms perhaps no creature 
aided more in carrying conviction to the 
mind of Dawin himself, and to countless 
other people, than the common domestic 
pigeon. For most of the domestic animals 
it is usual to bring in a hypothetical, 
fossil type, so widely have the living forms 
departed from any living wild types, and so 
true to the domestic types do the offspring 
hold; but with the pigeon it is not uncom- 
mon that reversions to the parent form 
occur, and even in the most modified forms 
reversions occur, so that there is substantial 
agreement that the parent stock is the wild 
rock pigeon (Columba livia). That there 
should be reversions in some forms is as- 
tounding, for even the number of vertebree 
has become changed by domestition. 
If, then, this study of domesticated and 
cultivated forms has thrown so much light 
upon this great subject of evolution as the 
method of nature, is there not promise of 
rich return for future study? And thereis 
need of future study, for only a beginning 
has yet been made in this great field. 
Let us now turn from Evolution to dis- 
cuss for a few moments the help which the 
SCIENCE. 
[N. 8. Vou. X. No. 245. 
domestic forms have given to Anatomy, 
Embryology and Physiology. 
If one asks of what animals the struc- 
ture is known in the greatest detail it must 
undoubtedly be answered that the structure 
of man has been most thoroughly explored, 
then come the domestic animals, especially 
the horse, dog, cat and rabbit. Much of 
this work was done before the doctrine of 
evolution illuminated the way and gaye 
meaning to rudiments or vestiges and to 
homologies. Still it mustbe said, in truth, 
that the older zoologists, with a rare insight, 
discussed large questions of homology, and 
recognized at bottom the real relationship 
of many different forms. It was, however, 
only the philosophical and far-sighted few 
who did so. The majority of anatomical 
work was done for its purely practical 
bearing on medicine and surgery. It thus- 
happened that human anatomy exerted 
a powerful influence, indeed, so powerful 
that names were carried over into the in- 
vertebrates, for parts which could hardly, 
by the greatest stretch of imagination, 
be homologous with the structures in 
man from which they were named. If 
there was any relationship it was of func- 
tion or analogy rather than that funda- 
mental kinship expressed by homology. 
Thus the legs of a horse and a spider are 
for the same general purpose. They are 
analogous, not homologous organs. There- 
fore, in many cases in the older morpho- 
logical work one should not be deceived 
by supposing that there was any real in- 
sight into the phylogenetic relationship of 
the two forms whose parts were similarly 
named. While there has been a great ten- 
dency to designate parts alike which have 
only a fancied or analogous relationship, 
there has been a more harmful tendency to 
ignore real relationships. Only purely 
practical ends have been too often in view, 
and the real kinship of forms as little 
known as cared about. 
