DECEMBER 17, 1897.] 
where he maintains that the first instinctive act 
(for example, the first peck of a newly hatched 
chick), the more automatic result of an inherited 
motor coordination, supplies to consciousness 
its first experience-data. ‘‘This is due to 
complex groups of incoming currents, from the 
parts concerned in the response, along afferent 
nerves to the sensorium.’’ On this first occa- 
sion the consciousness arises wholly by back- 
stroke. ‘‘Onsubsequent occasions, under asso- 
ciative suggestion, revivals in consciousness of 
previous experience-data modify the whole pro- 
cess and introduce the effective guidance of 
consciousness,’’ * * and * * ‘‘ This profiting by 
individual experience is of the very essence of 
intelligence.’’ 
If the revivals in consciousness are pleasur- 
able the activity is augmented; if unpleasant 
or painful itis inhibited. The repetition of the 
act becomes, then, a matter of conscious choice, 
and through reiteration the action becomes 
ingrained and habitual. ‘‘On this conscious 
selection and choice. depends * * * the deyel- 
opment of those habits which are acquired as 
opposed to those which are congenital; and 
* * * the whole mental as contrasted with 
merely biological evolution.’’ 
In treating of imitation, while it is admitted 
that there may be imitative organic response, 
independent of experience, the incentive to in- 
telligent imitation is the pleasurable sensation 
which the imitator receives when his acts re- 
semble the acts of others. The tendency to 
imitate is thus based on an innate proclivity, 
and is the means of securing to the organism 
a congeries of acquisitions which, perfected 
through repetition, may finally become habitual. 
In the opinion of Professor Morgan, already 
expressed in an earlier work, the value to the 
organism of the imitative tendency is vital. 
On its presence the questions of survival or de- 
struction frequently depend, for the imitation 
of the quick-witted and alert is often the salva- 
tion of the more stupid. In gregarious ani- 
mals, through ‘tradition,’ acquisitions are 
handed down from generation to generation 
without the aid of hereditary transmission. 
The motif in the chapter on ‘Emotions’ is 
the elaboration of the theory of James, namely, 
that the emotion originates, is primarily gen- 
SCIENCE. 
919: 
erated, by a back-stroke from the motor organs 
and viscera, and thus ‘all the data of sense ex- 
perience are of peripheral origin.’ Though 
Morgan’s observations appear to be in accord 
with this view, the reader may not feel thor- 
oughly convinced that the emotions are uniyer- 
sally the conscious effect of the back-stroke 
from the visceral actions. 
In the succeeding chapter the author shows 
that though an emotion is private to, and ex- 
clusively for, the individual receiving the back- 
stroke, the subsequent ‘expression’ may be, 
and often is, an indication to others of the par- 
ticular emotional state. ‘‘So long as the ex- 
pression indicates an emotional condition which 
shows that the animal means business, that is 
enough from the biological point of view.’? He 
thus incidentally reconciles Wallace’s theory 
of exuberant vitality with commonplace sexual 
selection. - Exuberance of vitality may be ex- 
pressed, on the one hand, by emotion (song, 
ete.), and, on the other, by peculiarities of struc- 
ture (plumes, ete.). Both may be of varying 
potency in arousing the sexual instinct of the 
opposite sex, and thus of varying selective 
value. ‘‘Stripped of all of its unnecessary 
eesthetic surplusage, the hypothesis of sexual 
selection suggests that the accepted mate is the 
one that most strongly evokes the pairing in- 
stinct.’’ 
The view is advanced that the song of birds, 
unlike their calls and alarm notes, may be 
‘traditional’ and due to imitation; and the 
question of the instinctive nature of the peculiar 
antics and aérial evolutions of certain birds, be- 
fore and during the breeding season, is raised. 
But ‘in all these matters further and fuller evi- 
dence from direct observation is to be desired.’ 
The sordid questions of domestic economy, 
nest-building, incubation, the care of young, 
etc., are now discussed and the questions raised : 
Are these phenomena instinctive or are they 
intelligent? Are they congenital or are they 
the result of individual experience? If in- 
stinctive, are they attributable to natural selec- 
tion alone, or to the inheritance of acquired 
habit? So far as certain of the phenomena are 
concerned, the author favors a possible coopera- 
tion of natural and intelligent selection, though 
he concludes that as matters stand ‘the ques- 
