254 ON THE STRUCTURE OF OSCILLATORI^. 



plants. On this head I would offer in conclusion a few 

 observations, in order to show that the present state of our 

 knowledge in this respect is far from satisfactory. 



Almost every day brings forth a discovery by which the old 

 landmarks established in science for the arrangement and 

 classification of the various products of our planet are unset- 

 tled, and this is more particularly the case as regards those 

 two kingdoms, the lower forms of which approach so near one 

 another, that, for want of distinctive characters, we cannot 

 always draw a positive line of demarcation between them, 

 'i'liis state of uncertainty, though partly the natural result of 

 the very nature and conditions of the objects to which it refers, 

 still prevails to a greater extent than is warranted, and must 

 continue to do so until our present notions on this subject 

 have undergone a thorough revision. In my opinion, the 

 boundary assigned to the vegetable kingdom is too limited ; 

 our definition of a vegetable organism must be enlarged, and 

 we may vindicate for plants many attributes hitherto exclu- 

 sively attributed to animals, though, as a necessary conse- 

 quence of the more limited sphere of activity characteristic of 

 vegetable life in general, they will necessarily be manifested 

 in a less prominent manner ; but this should not mislead us 

 so far as to ignore their existence altogether, and how vast a 

 difference in the manifestation of the various attributes of life 

 is observable even amongst animals themselves ? A plant is 

 generally defined as a natural body possessing organization 

 and life, but devoid of sense and voluntary motion. Orga- 

 nization and life exclude all inorganic bodies ; absence of 

 sense and voluntary motion the class of beings which are 

 comprised under the name of animals. Now a little consider- 

 ation will at once show us how arbitrary the limits are which 

 have been assigned to the vegetable kingdom in the latter 

 direction. By saying devoid of sense, is meant absence of 

 special organs of sensation, viz., nerves, and thus sensibility 

 is at once inseparably bound up with the existence of a 

 nervous system ; sensibility, however, is simply the peculiar 

 aptitude or capacity of organized living beings for receiving 

 impressions, but not necessarily through nerves only, neither 

 is it necessary that its effects should always be visible or ac- 

 companied by consciousness ; nerves presuppose sensibility, 

 but not, vice versa, sensibility nerves. Sensibility is something 

 prior to nerves ; a faculty, an attribute of every living or- 

 ganism, but not every living organism must necessarily possess 

 nerves ; nerves are only special organs characterizing tlie 

 manner of its manifestation in a certain class of beings. I 

 would remind the reader of the well-known instances of 



