122 SECTIONAL ADDRESSES. 
research on helminthes, and fertile in measures tending to reduce the 
risks of infection. 
Insects, protozoa and helminthes not only inflict direct injury on 
man; they also diminish his material welfare by impairing the health 
or causing the death of his horses, cattle and sheep, by destroying food 
crops during growth and, in the case of insects, by devouring the 
harvested grain. The measure of control which man can gain over 
insects, ticks and endoparasitic organisms, will determine largely the 
extent to which he can use and develop the natural resources of the 
rich tropical and sub-tropical zone of the earth. 
Other applications of zoology to human well-being cannot be dealt 
with owing to lack of time, but mention should be made of two—the 
researches on sea-fisheries problems which have formed an important 
branch of the zoological work of this country for forty years, and the 
studies on genetics which made possible an explanation of the mode of 
inheritance of a particular blood-group, and of some of the defects 
(e.g. colour-blindness and hemophilia) and malformations which appear 
in the human race. 
Maintenance of Correlation between the Branches of Zoology. 
The rapid expansion of zoology has brought in its train the difficulty 
of maintaining the connection between its different branches. There is 
not only the mental divergence of the different workers, due to the 
necessity for specialised reading, thinking, and technique, but also in 
some cases spatial separation, and this seems to me to be the factor 
of greater importance. When’ modern developments of the subject 
necessitate expansion of the staff and of the working facilities it has 
not infrequently happened that one of the newer branches of the subject 
has been placed in another building, and unless careful arrangements 
are devised the dissociation tends to become more marked, so that, to 
take Mr. Bateson’s example, the geneticist becomes separated from 
his colleague whose interests are more largely in systematic zoology, 
to their mutual disadvantage. 
The actively growing physiological branch of zoology will, it is 
to be hoped, remain an‘integral part of our subject; for while there 
are close and friendly relations between the Department of Zoology and 
the Department of Physiology, the latter is mainly concerned with the 
training of medical students, and the teaching and research are conse- 
quently, in most Universities, chiefly directed to the physiology of 
mammals and of the frog. The medical physiologist cannot be expected 
to prosecute researches on the invertebrates—these are as a rule too far 
removed from the matters with which he is especially concerned—and 
yet many of the invertebrates have’ been found 'to be especially favour- 
able for the investigation of fundamental problems which the morpho- 
logist with physiological leanings and training seems most fitted to 
undertake. It is a good sign that more students of zoology are including 
a course of physiology in their curriculum for the science degree, thus 
preparing themselves for work in comparative morphology and’ com-' 
parative physiology. | eat 
! 
