REJUVENESCENCE IN NATURE. 2] 



1.— THE FORMATION OF SPROUTS. 



There cannot be any doubt that the formation of 

 sprouts belongs to the class of the phenomena of Reju- 

 venescence, for with every sprout commences a new 

 train of development, the relation of which to the entire 

 developmental chain of the specific vegetable life, we have 

 here especially to investigate. The principal sprout of 

 the plant takes its origin from the seed, and is indeed 

 merely the direct development of the seedling (embryo), 

 thus grown up from the first point of vegetation of the 

 plant, which, traced backwards, leads to the primary 

 germinal vesicle. The lateral sprouts (branches), al- 

 though their origin is unconnected with the co-operation 

 of the sexes, agree with the main sprout in that they 

 also are developed from special centres of formation, 

 distinct, after their first origin, from the principal sprout. 

 We shall return in the sequel to the origin of the principal 

 sprout, with which every new vegetable " stock"* arises, 

 when examining propagation from the point of view of 

 cell-formation ; here we must occupy ourselves with the 

 lateral sprouts, which belong to the sphere of com- 

 pletion {Ausbildung) of the vegetable " stock" itself. 



Unfortunately we are deficient in thoroughly worked- 

 out researches on the origin of the lateral sprouts or 

 branches ; but so much is known, that the origin of the 

 sprouts is subsequent to that of the leaves, that they 

 derive their origin from the already more developed 

 tissues of the stem, while the first rudiment of the leaf 

 coincides with the earliest stage of formation of tissue 

 underneath the point of vegetation. f While the leaf, 



* The word " stock" is used here and elsewhere in the sense of what may 

 be called a phi/tidom (like a pohjpidom), indicating the total organically 

 connected structure composed of a number of partially independent links 

 or members. — Trans. 



t Vide Nageli, ' Zeitsohrift fur Wissensohaftl. Botanik,' Heft iii, iv, 

 pp. 1.53, 177. 



