I.] ADAPTIVE ATTRIBUTES. 51 



raorphous, and finally tend towards extinction. The 

 most flexible types of cultivated plants are such as have 

 probably not yet passed their zenith, as the cucurbits, 

 composites, begonias, and the like. The varieties of 

 cereals, which are old types, are so much alike that ex- 

 pert knowledge is needed to distinguish them. 



5. New types are more variable and flexible because 

 less perfectly moulded into and adjusted to the circum- 

 stances of life than the old types are. They have not 

 yet reached the limits of their dissemination and varia- 

 tion. They are generalized forms. 



The reader will please observe that I have here re- 

 garded the origin and survival of the unlike in the plant 

 creation in the sense of a plastic material which is acted 

 upon by every external stimulus, and which must neces- 

 sarily vary from the very force of its acquired power of 

 growth; and the unlikenesses are preserved because they 

 are unlike. I have no sympathy with the too prevalent 

 idea that all the attributes of plants are direct adapta- 

 tions, or that they are developed as mere protections 

 from environment and associates. There is a type of 

 popular writings which attempts to evolve many of the 

 forms of plants as a mere protection from assumed ene- 

 mies. Perhaps the plant features which have been most 

 abused in this manner are the spines, prickles, and the 

 like, and the presence of acrid or poisonous qualities. 

 As a sample of this type of writing, I will make an ex- 

 tract from Massee's " Plant World: " 



Amongst the most prominent and general modes of 

 protection of vegetative parts against the attacks of liv- 

 ing enemies may be mentioned prickles, as in roses and 

 brambles, which may either be straight, and thus pre- 



