NEW FORMATION OF ORGANS IN REGENERATION 



47 



shoots will be much longer in flowering. I have repeated this experiment 

 with Achimenes with a like result (see Fig. 19): leaves from the flower- 

 region produced adventitious shoots which flowered much sooner than 

 did those upon leaves which were taken from the basal region of the 

 plant ; the former produced usually only one to two leaf-pairs which 

 had no flowers in their axils, the latter had always a greater number of 

 pairs. Sachs concluded from his experiments that the flower-forming 

 material was already in existence in the leaves of the plants which were 



FlG. 19. Achimenes Haageana, a garden hybrid. A leaf of a. plant ripe for flowering has been used as a leaf- 

 cutting ; at the basal end of the severed leaf-stalk an adventitious shoot has developed which has already reached 

 the stage of bearing flowers. 



ready to bloom. One could also say that the leaves of plants which are 

 ripe for flowering will be generally poorer in plastic material, that the 

 adventitious shoots which they produce would therefore from the beginning 

 be ' enfeebled,' and we know empirically that the formation of flowers is 

 favoured by lessening of the vegetative growth. 



In mosses the propagative capacity is uncommonly great ; one may 

 almost say that nearly every cell of the vegetative body in mosses and 

 liverworts, and in part also the cells of the sporogonium which is generally 

 still capable of development, can give rise to a new plant. In the 



