PLANT HYBRIDIZATION BEFORE MENDEL 199 



ing the growth process, returning with the formation of the em- 

 bryo to its original constitution in the initial cell, or else it main- 

 tains the same constitution, and the altered conditions of time and 

 place in the individual's life-history affect its potentiality, (p. 30.) 

 Attention is called to the fact that a branch with different char- 

 acters from those of other branches, may grow out from a tree, 

 a case, manifestly, in which external conditions do not come into 

 play. In such cases, the idioplasm has evidently undergone a 

 phylogenetic metamorphosis, (p. 31.) It is assumed to be possible 

 for the idioplasm to change within definite limits, during indi- 

 vidual growth. The idioplasm of each of the different cells of 

 an individual may be considered, for practical purposes, as differ- 

 ent, "insofar as it possesses an individual productive capacity." 

 (p. 31.) The development into activity of the Anlagen in the 

 idioplasm is conditioned to some extent by the nutrition, e.g., 

 whether, in the case of certain trees, foliage or flower shoots are 

 formed, or vegetative growth without flower formation at all, 

 under unfavorable climatic conditions, (p. 32.) The variety in 

 the growth processes in the idioplasm is conceived of as possible 

 in the following manner : The idioplasmic structure represents a 

 fixed arrangement, and its parts (the micellae) may be conceived 

 of as lying in rows in several dimensions crossing one another, 

 so that the same particle always belongs to rows of divergent 

 space-dimensions. Growth of the idioplasm is the growth of these 

 rows through the accession of new micellae, uniformly interca- 

 lated, or through end-deposition. The idioplasm may increase 

 either through the growth of the rows alone, through the exten- 

 sion in width of the cross-rows, or through the growth of rows 

 in some oblique direction. The growth of the rows in question to 

 some determined dimension results in the development of a defi- 

 nite "Anlage." (p. 34.) This structure of an idioplasmatic system, 

 Nageli holds, is analogous to that of other organized bodies, 

 which consists of crystalline micellae, comprising a larger or 

 smaller number of molecules. 



"The starch grains give us a presentment of the idioplasm. Both are 

 fixed micellar systems, which lie free in the cell contents, in the cell-sap 

 or in the half-fluid plasm, and which grow through the intercalation of 

 micellae." 



The idioplasm, constructed as surmised above, "can be known 



