438 / ARTHUR THOMSON [june 



of results, no permanent steps of real moment are likely to be made. 

 This note of the unity of the sciences is sounded whenever we say the 

 word university. Its value is demonstrated by the history of the 

 sciences, which shows how often a fresh contact between two depart- 

 ments — chemistry and biology, biology and psychology — has led to 

 great advances. It is also demonstrated when we consider a big- 

 subject, like the physiology of marine organisms, which there is no 

 hope of understanding except through the combined efforts of chemist 

 and physicist, botanist and zoologist. How hopeless it would be for 

 the unaided biologist to suggest an answer to the recent question — 

 Why is the population of swimming and drifting marine organisms 

 denser in the arctic than in tropical or sub-tropical seas ? Whether we 

 take a hint from the way in which Linnaeus used the term 

 " Organisata " to include both animals and plants, or from the title 

 " Animated Nature " which the keen-witted amateur Goldsmith used, 

 or from Comte's hierarchy of the sciences, or from the late Principal 

 Caird's essay on the unity of science — I have purposely chosen 

 incongruous examples — we hear the same note of unity towards which 

 our teaching and learning must move, even if the curve be asymptotic. 

 The study of living creatures stands midway between the chemical and 

 physical sciences, which are in a sense beneath it, and the mental and 

 social sciences, which are in a sense above it ; there are lights from 

 beneath and lights from above ; and to attempt to shut out either 

 means obscurity. It is evident, for instance, to every one who has 

 considered the matter with an unbiassed mind, that what are called the 

 evidences of organic evolution owe much of their cogency to corrobora- 

 tions from other sciences than biology. 



The Life, of Living Creatures. 



The second note which seems to be sounded by the old naturalists 

 who clung to the term " natural history " — men like Gilbert White, for 

 instance — suggests that our first and our final problem is with the life 

 of living creatures in a state of nature. Amid the undoubted and 

 surely legitimate fascinations of dissection and osteology, of section- 

 cutting and histology, of physiological chemistry and physiological 

 physics, of embryology and fossil-hunting, and the like, do we not need 

 to be reminded sometimes that the chief end of our study is a better 

 understanding of living creatures in their natural surroundings ? In 

 what I may perhaps call the keenly analytic atmosphere of modern 

 zoology there is no risk that any one will fail to appreciate the value 

 of the abstractions which we make when we study the dead beast on 

 the dissecting tray, or sections of parts of it under the microscope, or 

 solutions of parts of it in the test-tube — but is there not a risk lest we 

 forget that the picture and the problem with which the naturalist 

 starts, and to which he must eventually return, is the picture and the 



