272 SIMPLEST MODES OF REPRODUCTION. 



424. In the lowest plants, the process of reproduction is as 

 simple as that of their growth. Each single cell of the Red 

 Snow (. 48, Fig. 14) for example, produces within itself a num- 

 ber of little particles ; which, at a certain period, are set free by 

 the bursting of the parent-cell which incloses them. These 

 granules then gradually enlarge, deriving their nourishment 

 from the air and moisture around ; and in time they acquire the 

 size of the parent plant, and in their turn produce a new family 

 within themselves, which at the proper time they set free. A 

 similar process takes place in the Yeast-Plant (. 56, Fig. 18). 

 In the Confervas (. 41, Fig. 11), in which a number of cells 

 are united together, end to end, in each filament, the several 

 cells in like manner set free from their interior the little green 

 particles, which serve to propagate their kind ; but the parent 

 cells do not lose their own lives, in thus sending a new generation 

 into the world ; for, instead of bursting, they allow the granules 

 to pass out by a small aperture which forms in their walls. The 

 growth of these particles within the parent cell may be distinctly 

 traced : at first they are seen adhering to its inner wall ; then 

 they separate themselves from it, and float in the fluid it con- 

 tains ; then they are seen to move, while yet within the cell ; 

 and after they have passed out, they continue their motion, even 

 in an increased degree, for some time. At last they attach them- 

 selves to some fixed object, and their development into new 

 plants then begins. The particle gradually enlarges, and forms 

 a cell containing fluid ; this cell takes an oval form, and a parti- 

 tion then appears across it, dividing it into two ; one of these is 

 elongated in the same manner, and is again subdivided ; so that 

 at last, a complete filament, consisting of many cells, is produced ; 

 this, in its turn, sends out reproductive particles from its cells, 

 which go through the same processes. The curious movement 

 of these granules (which any one possessing an ordinary micro- 

 scope may observe for himself, by watching the reproductive 

 processes in the common Confervas of our streams,) has given rise 

 to the notion, that they were to be regarded as animalcules, at this 

 stage of their existence ; a notion which is only mentioned here, 

 to point out its absurdity ; since, whatever may be the cause of 



