OF PLANTS. 69 



to the multiplication by seeds we shall presently speak of, 

 since it may be laid down as a pretty general rule, that the 

 less seed a plant ripens, the more it becomes multiplied by 

 buds, and vice versd ; Nature has here, as it were, taken 

 care that the plants shall be preserved under any circum- 

 stances. 



5. All the modes of reproduction hitherto noticed may 

 be placed together under the head of irregular propagation, 

 and be opposed to the regular propagation, which exhibits 

 essentially the following phenomena: Every plant pro- 

 duces within itself a definite number of single, free, uncon- 

 nected cells, which at a certain epoch spontaneously separate 

 from the plant. It is the peculiar character of those plants 

 which have true leaves, to produce these cells only in the 

 interior of the leaves, which at the same time often assume 

 a very different form, as for instance in the stamens. 

 Another condition is also worthy of remark. Only in the 

 very lowest plants, flowering wholly under water, is the 

 propagative cell naked (PI. in. Fig. 1) ; in all others, it is 

 invested with a peculiar substance, which has not yet been 

 chemically examined, but is mostly yellow and very inde- 

 structible. This substance frequently assumes very strange 

 forms. Sometimes it resembles little warts or spines, and 

 often little projecting ridges are formed, taking the shape 

 of arcades, battlements with turrets, &c. Nature, however, 

 has not yet given us the slightest clue to the possible 

 purpose of these varied forms. Elegant as they are, they 

 appear to be of no actual use. Fritsche, of St. Petersburg, 

 in a work especially devoted to them, has given representa- 

 tions of the most exquisite forms. Now these cells are 

 especially destined to the reproductive function, since from 

 every one of them is a new plant developed. An essential 

 distinction, however, occurs in this development ; one, 



