414 DEVIATIONS FROM 



whole of one set of organs be increased in size beyond 

 the recognised average, we have large varieties, often 

 quahfied by such terms as macrophylla^ longifolia, 

 macrantha^ &c. &c. In all these cases either the entire 

 plant or whole series of organs are alike increased or 

 diminished beyond average limits ; and such variations 

 are often very constant, and are transmitted by here- 

 ditary transmission. It may be supposed that such 

 deviations may have originated, in the first instance, 

 either from excessive use, or from disuse, or from the 

 agency of certain conditions promoting or checking 

 growth, as the case may be ; but whether or no, it is 

 certain that these variations often persist under difi*erent 

 conditions, and that they often retain their distinctive 

 characters side by side with plants presenting the 

 normal average dimensions. In other cases the varia- 

 tions in size are of a less general character, and affect 

 certain organs of a whorl in a relative manner, as, for 

 instance, in the case of didynamous or tetradynamous 

 stamens, where two or four stamens are longer than 

 their fellows, the long or short stamens and styles of 

 di- and tri-morphic flowers, &c. These differences are 

 sometimes connected with the development of parts in 

 succession, and not simultaneously. 



Teratological deviations of size differ from those of 

 which mention has just been made chiefly in this, that 

 they are more limited in their manifestations. It is 

 not, as a rule, the whole plant, or the whole series of 

 nutritive or of reproductive organs, that are affected, 

 but it is certain parts only ; the alteration in size is 

 more a relative change than an absolute one. 



For convenience sake the teratological alterations of 

 size may be divided into those which are the result of 



