16 PRESIDENTIAL ADDEESS, 



specialists. But now it is in vain for any one to attempt either 

 to advance physical science, or even to earn the slightest reputa- 

 tion, without devoting himself to some particular hranch, or to 

 some particular portion of the animal or vegetahle structure. 

 Thus the comparative anatomist must concentrate his study not 

 on the whole framework but on some particular portion in detail. 

 Prof. Parker has shewn what may be deduced from the careful 

 comparison of the shoulder blade alone in Yertebrates, Prof. 

 Huxley from the palatal bones in birds alone. Nitzsch has shewn 

 us what problems are involved in the single question of pterylo- 

 graphy. Others too numerous to mention, each taking their own 

 special subject as a fundamental note, and thence modulating 

 into other kindred keys, have borne testimony to the fact that 

 no subject is so special as to be devoid of bearing or of influence 

 on others. Some have described the successive stages of even a 

 single but important experiment, and while tracing the growth 

 of that particular item and of the ideas involved in it, have inci- 

 dentally shewn to the outer world what manner of business a 

 serious investigation is. JN'ow I conceive that in pursuing this 

 course the specialists have been exactly performing the function 

 most indispensable for the establishment of natural science on a 

 firm basis of ascertained fact. But the tendency of all scientific 

 students is at once to generalize from facts within their own spe- 

 cial sphere, and it seems to me that many of our current generali- 

 zations have been at the least premature, and that true wisdom 

 would be content for the time with the establishment of facts, 

 and leave the deductions to be drawn when the facts on the one 

 side and the other have not only been ascertained but have been 

 compared and balanced. Por the specialist is apt to become the 

 man of one idea, and is tempted to ignore counter-balancing and 

 resisting forces. The force which is under his immediate cogni- 

 zance he has watched, and measured, and calculated, but has he 

 duly considered the innumerable counteracting forces which re- 

 sist or bias on one side or the other the results of the one force 

 on which his attention is fixed ? Take for instance the problem 

 of classification. This can only be solved by a judicial examina- 

 tion of forces all impinging in different directions. If we take 



