LANDMARKS OF BOTANICAL HISTORY GREENE 73 



fore plants. Here it should be remarked that well toward the 

 beginning of the seventeenth century there were people among 

 these at least one very eminent botanical author who did not 

 allow the fungi to be classed as plants at all. Theophrastus knew 

 all these lower forms of vegetable life, fungi both terrestrial and 

 hypogeous, lichens and algae in abundance, and proclaimed 

 it unhesitatingly that they are plants; plants indeed without 

 stem or leaf or root or seed. 'The phases of plant life are 

 so exceedingly diverse in nature and constitution that, to give 

 a general (i. e., morphological) definition of a plant, and that 

 in few words, is not possible," 1 he savs. He ventures, however, 

 one distinctive peculiarity of plants. ' They are not, like animals, 

 endowed with ethical susceptibilities and the power of voluntary 

 action." This is metaphysical, indeed, yet no whit more so than 

 that which Linnaeus gave in the middle of the eighteenth century 

 when, pressed for one single mark of distinction between the genus 

 Homo as separate from those anthropoid mammals next in rank, 

 he was compelled to cite the " Nosce teipsum"; that is, man's 

 consciousness of his own existence. Between animal and vegetable 

 kingdoms the man of the eighteenth century could offer no better 

 distinction than this: "Plants grow and live. Animals grow, live, 

 and feel." 3 But he of twenty centuries earlier had been more 

 circumspect and cautious. Such movements as heliotropism and 

 nyctotropism, and others seemingly akin to nervous irritability, 

 were not unrecognized by Theophrastus, and may well have seemed 

 to indicate something too closely allied to feeling. 



In defining the manifest organs of higher plants the philosopher 

 proceeds with like caution, preferring physiological to morpho- 

 logical characteristics; in this, the first precursor of the modern 

 biologist, who, if required to name one distinction between plant 

 and animal, confines himself to a point in physiology. 



The root, Theophrastus says, is that by which aliment is taken 

 up 4 ; not a satisfactory definition to us moderns who demand 

 morphological distinctions. Yet very safe is Theophrastus in his 

 reserve; for what he names as characteristic of roots, albeit a 

 merely functional characteristic, is one that holds. It is also 

 apparently a new definition, framed by himself, and intended to 



1 Hist., Book i, ch. 2. 



2 Hist., Book i, ch. i. I trust I may not be found to have rendered too 

 freely the words fiOy and 



* Syst. Nat., 4th ed., p. 3. 



* Hist., Book i, ch. 2. 



