1905.] NATURAL SCIENCES OF PHILADELPHIA. 163 



the morphological and the experimental. The former reasons out the 

 process as it is to be understood from the sequence in structural 

 change ; the latter aims directly at an analysis of the process by a study 

 of result where the cause is measurable. Yet just here it must be held 

 in mind that the true morphologLst has in ultimate consideration the 

 explanation of process, so that he is fully as much a physiologist as 

 the other. And his method is correct, because structure only is visible 

 while process is an intangible change, and therefore he is reasoning 

 from the perceptible to the imperceptible. Many morphologists do 

 not conceive this mental attitude rightly, and most physiologists are 

 inclined to hold that all morphologists see no further than the struc- 

 ture. Yet the morphological basis must precede the physiological 

 experiment, and it is quite questionable whether both will not always 

 be necessary as complemental methods ; we cannot say which w^ll ulti- 

 mately prove the more important, but all will admit that the greater 

 interpretations of biology have had a morphological basis, and that the 

 morphologist has done his full half in reasoning out the processes. 



That is not scientific morphology which goes no further than the 

 structural fact; but with minor exceptions all morphologists try to 

 go much further than this, and throughout their analyses have in 

 mind the process. And the morphologist is an analyst of natural phe- 

 nomena, an explainer of those normal experiments not performed with- 

 in the laboratory. Therefore a present tendency to maintain that only 

 experiment can furnish explanations, and that structural study can 

 present only observational results, has no foundation whatsoever. 

 The true method is to remember always that in the living as in the non- 

 living world the process must be interpreted ; so long as this is not for- 

 gotten it matters little what mould the investigation is cast in. 



Some years of rather intensive study of the structure of the germ 

 cells, particularly of the behavior of their, chromosomes, has led me to 

 the conclusion that there is simplicity and essential uniformity among 

 the bewildering maze of the observable. When we strive to explain 

 the more complex from the more simple we discover this uniformity, 

 but not when we stubbornly persist in regarding the more complex as 

 the condition that can be immediately explained. Complete agreement 

 of opinion there may never be, but this is because of mental differences 

 and not of lack of uniformity in the natural processes. A main reason 

 for the failure to interpret the uniformity has come from one of 

 three preconceptions : of persistent study of an object which has shown 

 itself incapable of furnishing a clear solution; consequently of the 

 neglect of seeking comparative evidence ; and of loyalty to the views 



