No. 391.] REVIEWS OF RECENT LITERATURE. 615 
wholly upon those secondary results of mental activity which are 
expressed in the form of physical changes. From these he must 
analogically reconstruct the set of psychical changes which it is the 
intention of his psychology to describe. His way is thus beset with 
peculiar difficulties, and every precaution must be taken to guard 
against false interpretation of the data. Reaction from the flagrant 
error of freely reading human motives and play of ideas into the 
actions of the lower animals must not lead us into the equally false 
position of assuming that the simplest explanation of such conduct 
must necessarily be the true one. When my dog follows me to the 
corner of the street and, on seeing me turn in the direction of the 
market square where he has been roughly used, instead of toward 
the college yard whither he has always followed me with delight, 
drops suddenly upon his haunches, watches my steps a moment, and 
then turns homeward, his action is to be explained in accordance 
with the more complex hypothesis, not with the simpler. His inter- 
est has not died out, nor has a new object attracted him. The desire 
to accompany me is still a living motive, but its effect is transformed 
into an act of the opposite nature through the more powerful motive 
of fear. This is but an illustration of a condition of affairs which is 
constantly met with, in which the advocates of the simplest explana- 
tion are wholly out of court. Inhibition plays a tremendous part asa 
determinant of action in the lower animals, and the deficiency of our 
accounts of their mental life is doubtless in part due, as Professor 
Mills says, to the fact that “insufficient attention has been given to 
distinguishing between normal, sub-normal, and super-normal com- 
parative psychology,” and especially, I may add, to the lack of an 
intimate study of the relation of the animal to its environment with 
regard to the facts of inhibition and disturbance of normal motivation. 
ROBERT MacDouGaLt. 
ZOOLOGY. 
Some Japanese Oligochata.— In the course of the year 1898, 
three papers on “ Japanese Oligocheta ” appeared in the Annotationes 
Zoblogice Japonenses, which materially extend our knowledge of this 
division of Japanese fauna. In the first of these— “On a New 
Species of Littoral Oligocheta” (Pontodrilus matsushimensis )' — 
Akira Iizuka describes a new species of Pontodrilus 
1 Annotationes Zoölogice Japonenses, vol. ii, Pt. i, pp. 21-26. 
