of the Organic Systems of Vegetables. 87 



fervae ? what the vegetation of tuber ? of the fuci ? of many 

 rushes, of the Cacti, e. g. C. opuntia, C. melocactus? &c., &c. 

 It would be difficult to say from ordinary definitions whether 

 in some of these examples either root or stem be present, and 

 whether in others they are leaves entirely, or whether they have 

 no leaves at all ; though, from their increase both in size and 

 number, it is manifest that both the nutritive and reproductive 

 systems are present, and as energetic, as efficient in them as in 

 more highly developed individuals. 



Let us, on these principles, pursue the analysis of a plant. 

 Let the three primary systems of the vegetable organism, 

 separable in idea, though not separate in nature, be figura- 

 tively represented by three spheres or circles, more or less 

 containing and contained in each other ; these are the nutrient, 

 the stock, and the generant, or the organs of nutrition, exten- 

 sion, and reproduction. In the simplest protophytes these 

 three essential systems are equally present and equally undis- 

 tinguishable from each other ; in the lower confervae, in the 

 tremellae, &c., every part absorbs and nourishes equally, and 

 every part will equally reproduce an individual like that from 

 which it is disjoined ; the generative molecules not being pro- 

 duced in or confined to any especial part, as are seeds and 

 buds to flowers and stems, but scattered indifferently through- 

 out the substance of the plant. Again, in some of the higher 

 algae and the musci distinct and separate roots appear ; and in 

 the fuci and lichens the spores are chiefly situated in peculiar 

 parts, i. e., in certain discs, or thalami, at first being aggre- 

 gated internally towards the surface, and then becoming exter- 

 nal tubercles. Among the fungi also, at least among the more 

 developed ones, a still further segregation may be noted, in the 

 formation of lamellae or pores for the reception of the sporules. 



These illustrations might be multiplied and the thread of 

 organic evolution be pursued through the whole of the vege- 

 table reign, but here the cumulative argument is needless. 

 The fact might be allowed to rest on the bare enunciation 

 that these three systems are present in every plant, though 

 variously distinct or intimately blended with each other ; and 

 that no one is ever truly, however all may in turn apparently 

 be, absent. All plants must have, as postulates of their exist- 



