120 THE DIRECT INFLUENCE 



leaf causes adjustments in the remaining ones, 

 and instances might be multiplied almost indef- 

 initely to show that effects produced in one part 

 are qxiickly and forcefully transmitted to other 

 parts of the soma. It matters not for the pres- 

 ent whether the means of communication be spe- 

 cial tracts, nervous mechanisms, chains of cata- 

 lytic reactions, or what other method of com- 

 munication. 



THE ACTION OF SOMA UPON GEEM-PLASM 



Similar communications between the egg and 

 soma are to be encountered. In some of the car- 

 potropic and gametropic movements of seed- 

 plants, the accomplishments of definite stages in 

 the development of the embryo-sac and fertiliza- 

 tion, result in impulses to stems and peduncles 

 several centimeters distant, producing move- 

 ments and morphogenic alterations of a very 

 striking character. Without further enlarge- 

 ment on this theme it is to be said that the securest 

 foundation is laid for the conclusion that well- 

 defined correlations exist in the plant by which 

 secondary effects of the action of external factors, 

 or of morphogenic or embryonic procedure, 

 may be freely communicated from one part of 

 the soma to another, and from the egg to the 

 soma. 



With such a substantial substratum of estab- 

 lished facts, we now turn to the problem as to 

 the communication of effects from the soma to the 



