158 SCIENCE AND PHILOSOPHY OF THE ORGANISM 



of structure in the outer protoplasmic layer, which is fixed, 

 be responsible for it, for there is no such structure there : 

 hence there must be a sort of feeling on the part of the 

 plant for its relative body localities, and on account of 

 this feeling morphogenesis occurs. This " feeling " is styled 

 " morphaesthesia ' : by Noll, and to it he tries to refer all 

 sorts of different botanical form-phenomena, 1 for instance 

 what is called " autotropism," that is, the fact that branches 

 of plants always try to reassume their proper angle with 

 regard to their orientation on the main axis, if this orienta- 

 tion has been disturbed. It may be an open question if 

 this particular application of the theory is right : certainly 

 there seems to be much truth in the establishment of the 

 concept of morphaesthesia, and we only have to object to 

 its psychological name. But that may be done in a more 

 general form on a later occasion. 



RESTITUTIONS OF THE SECOND ORDER 



In the hydroid polyp Tubularia, already familiar to us 

 us being a most typical representative of the harmonious- 

 equipotential systems, a very interesting phenomenon has 

 been discovered 2 , almost unparalleled at present but never- 

 theless of a general importance, a phenomenon that we may 

 call a restitution of a restitution, or a restitution of the 

 second order. You know that the first appearance of the 

 new head of Tubularia, after an operation, consists in the 



1 Certain phenomena of the physiology of growth of Geranium Robertianum, 

 recently discussed by France* from a vitalistic point of view (Zeitschr. Entw. 

 lehre. 1, 1907, Heft iv.), might also belong here. I cannot see an independent 

 proof of vitalism in these facts if taken by themselves ; a pre-existing 

 "machine " cannot be absolutely excluded here. 



- Driesch, Arch. Entw. Meek. 5, 1897. 



