200 PLANT HYBRIDIZATION BEFORE MENDEL 



only in one dimension, namely, in that in which its autogenetic 

 growth takes place." However, the idioplasm in an individual 

 propagating vegetatively may retain its arrangement unchanged 

 to the smallest particular. This fact, it appears, can be explained 

 in no other way than by the fact of the idioplasm being ar- 

 ranged in firmly converging parallel rows, which grow through 

 micellar intercalation, the structural arrangement remaining the 

 same. (p. 38.) 



One assumption, which as Nageli says, "is scarcely to be proved 

 out of hand," is that the idioplasm constitutes a connected net 

 throughout the entire organism. 



"This will assume in the cells, according to their construction, a differ- 

 ent form; ordinarily, however, in the longer plant cells, forming a mem- 

 brane over the surface, frequently also running through the cell cavity 

 and especially crowded together in the nucleus." (p. 41.) 



Since all the chemical and plastic processes of an heritable 



nature are regulated through the idioplasmic fibrils, these must 



be everywhere present throughout the different parts of the cells, 



and communication must be supposed to take place between the 



idioplasms located in the different parts of the organism. 



"The idioplasm-net probably lies at the basis of the so frequently 

 recurring net-like arrangement of the plasma, and the net-like structure 

 of the nuclear substance." (p. 41.) 



The idioplasm is conceived as originating the trophoplasm, and 

 thereby the non-albuminous constructive material, and determines 

 the form of the latter, fp. 47.) Nageli considers that the irritabil- 

 ity of the micellar rows of the idioplasm is not to be expressed 

 in terms of periods similar to those of nerve-activity, but that it 

 extends over a longer time — days, weeks, and months, during 

 which time the active idioplasm increases, fp. 47.) 



Nageli considers it improbable that the growth of the micellar 



row itself determines the development of the corresponding "An- 



lagen," but rather that both phenomena are brought about by a 



like cause. 



"The effect, which the idioplasm group, engaged in active growth, 

 exercises upon the surrounding idioplasm, may occur in a manner simi- 

 lar to that exerted by the plasma of the yeast cells upon the fermenta- 

 tion material." (p. 48.) 



The process of operation of the micellar rows of the idioplasm 

 Nageli considers theoretically to be as follows : 



