PRELIMINARY DISCOURSES. XiU 



II. ORGANIC BODIES living, heterogeneous, growing by intus- 

 susception ; two kinds, 



1. One kind, destitute of sensation, of voluntary! y e g e tdbles 

 motion, and of a stomach. / 



2. The other, endowed with sensation, capable of \A- ^ 

 voluntary motion, and provided with a stomach. / 



Certain Naturalists have been so forcibly impressed by the con- 

 templation of the gradual and near approach of the two great 

 divisions of organized beings, that they have thought we should 

 admit of but a single class, which they have designated* by the 

 name of the organic kingdom:. Others, again, have proposed to 

 establish an intermediate kingdom, between animals and vegetables, 

 to consist of Zoophytes, Sea-weeds, and Mushrooms. Both pro- 

 positions, however, have been rejected by the generality of Natural- 

 ists, with great unanimity. 



On this head, and in further illustration of the subject, the 

 eminent Author here cited remarks that those being& which seem 

 to us to be intermediate between animals and plants, ought rather 

 to be considered as evidences of our ignorance, than as proofs of 

 the existence of a peculiar class-; and although it may be correct to 

 Bay, that the two organic kingdoms havfrsuch striking resemblances, 

 and approximate so nearly, that a satisfactory line of demarcation 

 cannot be drawn, they nevertheless present differences of such a 

 character that it is useful to separate them, seeing that these dif- 

 ferences exert an influence upon the progress of the study, in 

 the two kingdoms, and consequently upon the logic of the two 

 Sciences. 



Assuming as a fact or as an extremely probable hypothesis 

 that Animals are endowed with sensibility, and that Vegetables are 

 destitute of it, we shall see resulting from that supposition, nearly 

 all the differences that we observe between animals and plants ; be- 

 tween Zoology and Botany. 



Since Animals have a consciousness of their existence, and a 

 sensation of pain and pleasure, it is natural to suppose that they 

 should endeavor to avoid the former sensation, and seek the latter, 

 that is to say, that they should be endowed with the faculty of 

 voluntary motion ; for, if we supposed them destitute of this faculty, 

 we should have no means of ascertaining their sensibility. Plants, 

 on the contrary, can perform no other motions than those which are 

 produced by external agents, or by certain mechanical circum- 

 stances of their structure. These motions can be neither voluntary, 

 nor truly locomotive. 



