EXPERIMENTAL MORPHOGENESIS 157 



little doubt that we have here an important feature with 

 regard to general morphogenesis. 1 



A few other groups of morphogenetic facts may find 

 their proper place here, though they are not properly to be 

 regarded as additions to the theory of harmonious systems 

 but as forming a sort of appendix to it. 



THE " MORPHAESTHESIA ' OF NOLL - 



We may briefly mention that group of botanical 

 phenomena, by which the botanist Noll has been led to 

 the concept of what he calls " morphaesthesia," or the 

 " feeling " for form ; a concept, the full discussion of which 

 would lead to almost the same conclusions as our analysis 

 of the harmonious systems has done. In the Siphoneae, a 

 well-known order of marine algae with a very complicated 

 organisation as to their exterior form, the protoplasm which 

 contains the nuclei is in a constant state of circulation 

 round the whole body, the latter not being divided by 

 proper cell-walls. On account of this constant movement 

 it is certainly impossible to refer morphogenetic localisation 

 to definite performances of the nuclei. Nor can any sort 



1 Reciprocal harmony may be reduced in some cases to the given pro- 

 portions of one original harmonious system, from which the single constituents 

 of the complicated system, showing reciprocal harmony, are derived. Then 

 we have only an instance of "harmony of constellation " (see p. 109). But 

 reciprocal harmony seems to become a problem itself, if it occurs in 

 restitutions starting from quite a typical point, selected by the experimenter. 

 It will be a problem of future research to give an exact formula of what 

 happens here. Reciprocal harmony also occurs in regeneration proper. It is 

 known that the formation of the regenerative bud and the differentiation 

 of this bud follow each other. As the bud is composed of different elementary 

 systems, it follows that these different systems, of which every single one is 

 harmonious, also have to work in reciprocity to each other, in order that 

 one whole proportionate formation may result. 



2 BioL Centralblatt. 23, 1903. 



