INTUODUCTOEY ESSAY. 17 



and from the ovule to the ripe seed, are all essential points ; 

 all, however minute, must in many cases be actually inspected 

 before the position of a doubtful genus can be ascertained in 

 the Natural System ; and this is not the exception, but the rule. 



The necessity for acquiring so extensive and detailed a 

 knowledge indicates a power of variation in those organs from 

 which the natural characters are drawn, that defeats any at- 

 tempt to render one, or a few of them only, available for the 

 purposes of classification ; and hence it is that the study of 

 morphology, or the homologies of the organs, becomes indis- 

 pensable to the systematist : by this he reduces all anomalies 

 to a common type, tests the value of characters, and develops 

 new affinities. The number, form, and relative positions of 

 organs may supply technical characters, by which observers of 

 experience recognize those natural orders under which a great 

 number of plants arrange themselves; but a knowledge of 

 structure and anatomy alone enable the botanist to progress 

 beyond this, and to define rigidly : whilst the study of deve- 

 lopment affords him safe principles upon which to systema- 

 tize and detect affinities, and morphology supplies the means 

 of testing the value of the results, and reveals the harmony 

 that reigns throughout the whole vegetable world. 



Physiology, again, is a branch of botany very much apart 

 from these : its aim is the noblest of all, being the elucidation 

 of the laws that regulate the vital ftinctions of plants. The 

 botanical student of the present day, however, is too often 

 taught to think that getting up the obscure and disputed spe- 

 culative details of physiology, is the most useful elementary 

 information he can obtain during the short period that is given 

 him to devote to botany*; and that, if to this he adds the scru- 



* As we are writing in the hope of being useful to our medical brethren 

 amongst others, we may be excused from remarking here, that it is not to the 

 credit of our medical curriculum, that, travel where we will, we find the medical 

 man deploring his inability to apply the knowledge of botany obtained at his 

 college, to any useful purpose. The httle he has learned about the names and 

 functions of organs he might easily have acquired at school, and thus have been 

 prepared to devote the whole period of liis botanical studies to the practical ap- 



d 



