104 



SCIENCE 



[N. S. Vol. XLIX. No. 1257 



tion and investigation of fields whose inune- 

 diate contribution to human welfare may be 

 difficult to discern. It is a well-known fact 

 that many of our most important advances in 

 applied zoology have been possible only with 

 the basis of knowledge acquired in some field 

 that seemed quite tmrelated to human affairs. 

 Instances will occur to all but such stock ex- 

 amples as the ecological relations of trichina, 

 liver fluke and other parasites may serve to 

 emphasize the point. 



It may be suggested then that one of the 

 great objectives for the immediate future is 

 carrying forward our researches on all fronts, 

 that we may secure cooperation and correla- 

 tion in the various lines and that we aim at a 

 more complete and perfect combination of 

 fundamental knowledge, which may be access- 

 ible from all sides for the furtherance of such 

 applications as may be needful in human 

 progress. 



Whatever our objective, it is interesting to 

 inquire as to owe conditions for progress, the 

 lines of work that we may see most clearly 

 ahead of us, the agencies through which we 

 may press for their attainment and the helps 

 or handicaps that are to be reckoned with in 

 our efforts. 



I feel sure no one will question the need 

 of continuous effort in the line of structure 

 both general and histological or of function 

 and activities in the widest sense for tissues, 

 organs and individuals. These constitute such 

 an imperative basis for all work in embryol- 

 ogy, life-history, activities and relationships 

 that only the most superficial view would per- 

 mit of a lessening of effort in these lines. 



As we go further in economic lines we ap- 

 preciate more and more that the control of 

 organic nature for the advantage of man 

 must be based on the most complete knowl- 

 edge of the structures, functions, habits, re- 

 sponses and relationships of the organisms 

 with which we must deal. Can we say of any 

 animal that we know all about it, that needs 

 to be taken into account, when we attempt to 

 fix its place in nature or with reference to the 

 organisms with which it may be associated? 



Have we by any means exhaused the prob- 



lems of structure, the physical factors in ani- 

 mal symmetry or correlation of organs or of 

 the activities of animals in many phases. 

 What of the mechanics of flight or aerial lo- 

 comotion as exhibited in various groups? 

 How do certain insects hover or fly backward, 

 as in many different families or even fly up- 

 side down as is claimed for certain tabanids. 

 And once these questions are satisfactorily 

 answered there will stiU arise the question as 

 to how such complicated activities had their 

 origin, what were the structural bases on 

 which they were built and what the forces 

 that have operated in their evolution. Even 

 the ultimate problem as to the nature of life 

 itseK must be solved, if ever, on the basis of 

 those organic forces which though possibly 

 only combinations of simpler chemical or 

 physical forces are so indissolubly linked with 

 organic structure that this must be our base 

 of attack. 



To enter another field and one of recent 

 important strides, consider the wealth of un- 

 solved problems concerning the relations of 

 animals to their environment and to each 

 other. These present, especially for . the bio- 

 logical factors, some wonderfully intricate as- 

 sociations and the determinations except for 

 a given time and place, perhaps, an impossible 

 task, since the various elements are in con- 

 stant process of change. But many of the 

 more constant factors may be determined with 

 approximate accuracy and allowing for pe- 

 riodic variations may afford a basis for some 

 valuable deductions, even possibly, for useful 

 economic practises. To cite a particular in- 

 stance let me mention the study of the short- 

 tailed shrew by Shull. Here is a species 

 seldom attracting attention but widely dis- 

 persed, occurring in great abundance and with 

 a variety of food that includes a large number 

 of species that we consider very injurious 

 along with many that are innocuous or pos- 

 sibly even beneficial. Doubtless we would 

 find a different bill of fare for the species 

 for every month of the year and possibly for 

 every field in which we might study it, but 

 the total appears to be decidedly in the ani- 

 mals favor. 



