283 THE PHENOMENON OF 



eesses of division are connected, in the first place, the 

 development of the tissue with its varieties, even the 

 development of the contrasts of the external organs (in 

 the higher plants), and, lastly, the multiplication of the 

 individuals, both through vegetative increase, and through 

 true reproduction. The formation of free reproductive 

 cells, may also be termed division, in so far that their origin 

 depends upon a parting of the contents of the mother- 

 cell. In opposition to this effort towards division and 

 separation, towards the development of multiplicity, both 

 from the repetition of the like and the shaping out of the 

 various vital tendencies in structures of many kinds — the 

 plant manifests, on the other hand, in certain periods of 

 conclusion and transition, an effort toward reunion of the 

 divided, either by gathering up and combining the 

 homogeneous, or- bringing together opposites. In the 

 higher divisions of the vegetable kingdom we meet with 

 this phenomenon in many forms. The intimate com- 

 bination of the organs at the higher steps of the meta- 

 morphosis, the fusion of parts in the individual whorls of 

 the flower, adherence even of entire whorls to each other,* 

 but in particular the blending of the carpels into closed 

 germens, exhibit the effort at reunion of the separated in 

 the morphological field, as the phenomena of fecundation 

 do in the physiological. But even in the lowest plants, 

 which do not possess the variety of organs and the con- 

 trast of sexes, whose whole cycle of vegetative life is 

 limited to the development of a single cell, or a series of 

 similar cells, we find acts of this uniting and collecting 

 vital tendency. Among the principal of these is the 

 phenomenon occurring in the Algae and Pungi, to which 

 the name of conjugation of the cells has been applied ; a 

 phenomenon which always occurs at the close of the vegeta- 

 tive development, ordinarily at the termination of a series 

 of unicellular generations produced by dividing-increase, 

 and is for the purpose of forming, directly or indirectly, 



* Whence arise the perigjnous and epigynous insertions. 



