ELEMENTARY MORPHOGENESIS 51 



and truly elemental, that alone may they be said to have 

 "described"; but they have " explained ' : by the aid of 

 elemen tali ties what proved to be not elemental in itself. 1 



It is the method of the physicists not their results 

 that morphogenesis has to apply in order to make progress ; 

 and this method we shall begin to apply in our next lectures. 

 Physiology proper has never been so short-sighted and self- 

 satisfied as not to learn from other sciences, from which 

 indeed there was very much to be learned ; but morphology 

 has : the bare describing and comparing of descriptions has 

 been its only aim for about forty years or more, and lines 

 of descent of a very problematic character were its only 

 general results. It was not seen that science had to begin, 

 not with problematic events of the past, but with what 

 actually happens before our eyes. 



But before saying any more about the exact rational 

 and experimental method in morphology, which indeed may 

 be regarded as a new method, since its prevalence in the 

 eighteenth century had been really forgotten, we first shall 

 have to analyse shortly some general attempts to understand 

 morphogenesis by means of hypothetic construction ex- 

 clusively. Such attempts have become very important 

 as points of issue for really exact research, and, moreover, 

 they deserve attention, because they prove that their authors 

 at least had not quite forgotten that there were still other 

 problems to be solved in morphology than only phylo- 

 genetical ones. 



1 We shall not avoid in these lectures the word "explain " so much out of 

 fashion nowadays. To " explain " means to subsume under known concepts, 

 or rules, or laws, or principles, whether the laws or concepts themselves be 

 "explained" or not. Explaining, therefore, is always relative: what is 

 elemental, of course, is only to be described, or rather to be stated. 



