306 SCIENCE, 
A glance at the tabular arrangement of 
the domestic animals will show where they 
are situated in the animal kingdom. In 
the great group of Invertebrates the two 
domesticated species—the Honey-Bee and 
the Silk- Worm—may be properly compared 
to minute islands ina greatocean. Among 
the Vertebrates, on the other hand, the 
domestic forms are represented in two of 
the six classes, viz.: in the Birds and 
Mammals, and where represented are 
among the most prominent and important 
members of the various orders: 
DOMESTIC INVERTEBRATES. 
The Honey-Bee (Apis mellifica). 
The Silk-Worm ( Bombyx mori). ‘ 
DOMESTIC VERTEBRATES. 
Class Aves—Birds. 
Goose ( Anser cinereus). 
. Natatores { Duck (Anas boschas). 
Swan (Cygnus gibbus). 
2. GRALLATORES— Waders (no domestic forms). 
Hen (Gallus domesticus). 
3. Gallinaceze ; Turkey (Meleagris americana). 
Peacock ( Pavo cristatus). 
. Columbinze—Pigeon (Columba livia). 
= 
oO 
etc.). (No domestic forms. ) 
. Passeres—Canary Bird (Serinus canarius). 
7. RAPTORES—(Formerly the Falcon was in a sense 
domesticated ). 
8. Cursores—Ostrich (Struthio camelus). 
for) 
Class—Mammalia. 
(A) MonotreMata (Forms which lay eggs). 
(B) MARsUPIALIA (Forms without true placenta). 
ORDERS OF PLACENTAL MAMMALS. 
1. EpENTATA—Armadillo, sloth, etc. 
. CETACEA—Whale, porpoise, ete. 
3. SIRENIA—Manatee and Dugong. 
( Horse ( Equus caballus). 
Ass (Equus asinus). 
Pig (Sus scrofa). 
_ f Camelus dromedarius. 
\ Camelus bactrianus. 
c) 
Camels » 
4. Ungulata J am 
Sheep (Ovis aries). 
Goat (Capra hircus). 
Ox ( Bos taurus ). 
| Elephant ( Elephas indicus). 
Cat (Felis domestica) . 
Dog (Canis familiaris). 
.. { Rabbit ( Lepus cuniculus). 
Oy etek ( Guinea Pig (Cavia cobaya). 
5. Carnivora 
. SCANSORES — Climbers (Parrots, woodpeckers, © 
[N. S. Von. X. No. 245. 
7. INSECTIVORA—Mole, hedgehog, etc. 
8. CHEIROPTERA—Bats. 
f§ Monkeys and apes. 
Op BOSS \ Man (Homo sapiens). 
NotE—In the table of birds the ordinal arrange- 
ment is that of Claus. It will be noted that five of 
the eight orders of birds have domesticated represen- 
tatives. Among placental mammals three of the 
nine orders are represented, the order Ungulata con- 
taining the larger number and the most important 
representatives. A few forms in addition to those 
named in the tables have been, at some time, more or 
less completely domesticated. 
With the personnel of the subject for dis- 
cussion thus fairly before us, what has been, 
what is, and what is likely to be the in- 
fluence of these forms in the rise and prog- 
ress of knowledge in.the broad field of 
zoology? Or more specifically, (1) What 
has been and what is likely to be the in- 
fluence of the study of the domestic animals 
upon the doctrine of the evolution of organic 
forms? (2) What has the study of them 
contributed in comparative anatomy, em- 
bryology and physiology? (3) What has 
been the contribution in hygiene and pre- 
ventive medicine? (4) And, finally, what 
should be their influence in theories of 
heredity and sociology ? 
If we would realize the value of the Doc- 
trine of Evolution, let us imagine for an in- 
stant that this doctrine of ‘ orderly change ’ 
were eliminated from the knowledge of 
men ! 
To turn the zoologist back to the old no- 
tions of special and independent creation 
for each species or group of animals, would 
be like leaving the astronomer only the 
sun-god, and the angels to direct the plane- 
tary movements. No, it is now next to im- 
possible to conceive of zoology struggling 
to comprehend the animal kingdom with- 
out this guiding principle. If similarity of 
form, color, structure and stages in embry- 
ology, function and even diseases are mere 
coincidences without further meaning, then, 
indeed, from a scientific standpoint, one 
