Vol. 43 T O R R E Y A December 1943 



Genetics, the Unifying Science in Biology* 



George H. Shull 



One may be excused for opening a paper on a subject of this kind by several 

 propositions of such obvious vaHdity that their statement is immediately recog- 

 nized as platitudinous : 



There is no wholly unrelated fact; all truth forms a connected fabric of 

 inconceivably vast, indeed of infinite extent. A single observation or any num- 

 ber of single observations between which no connection is recognized may each 

 and all be true, but they do not constitute science. Science consists of a body 

 of knowledge which rests on recognizedly related observations. The relation- 

 ships between observed facts are so numerous withal, and of so many different 

 kinds that it is utterly impossible for any single individual to apprehend and 

 comprehend more than a minute fraction of all that it is possible to know. 



It has been inevitable that the curiosity, that has led men to make sys- 

 tematic observations in order to add new facts related to those in which their 

 interest has been already aroused, has resulted in the sampling of many dif- 

 ferent parts of the network of observable phenomena and ascertainable rela- 

 tionships. Nature presents many different kinds of objects on which ob- 

 servations can be made, and among which relationships may be obviously 

 present or may be discovered if sufficient attention be given to them. With so 

 many different kinds of objects and different directions of approach there has 

 arisen a bewildering multiplicity of scientific disciplines, which, notwithstand- 

 ing their obvious overlapping and marginal merging with one another, have 

 tended inevitably to obscure the congruity of all facts and relationships in a 

 limitless universe. 



Of the observations, cogitations, inductive and deductive reasoning in 

 prehistoric times we know nothing but there is no reason to doubt that the 

 human mind exercised itself in all these ways just as it does today. The history 

 of biological science usually starts with the marvelously comprehensive work 

 of Aristotle, but there must have been many pre-Aristotelians of exceptional 

 intellectual capacity, whose intellectual acumen and keener-than-average 

 powers of observation gave them high quality as individual "natural philoso- 

 phers," but who, because of the lack of ready means of record and of inter- 

 communication, made no permanent impression on subsequent progress of 

 human knowledge and whose very existence can be only a matter of con- 

 jecture; they were the "mute, inglorious Miltons" of biological science, of 

 whom only a few fragmentary records, if any, remain. 



* Read at the 75th Anniversary Celebration of the Torrey Botanical Club at the 

 Brooklyn Botanic Garden, Thursday, June 25, 1942. 



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