METAMORPHOSIS IN PLANTS. 91 



to say that one of the main obstacles to the advance of 

 morphological Botany has been the failure to recognise the 

 distinctness of these two conceptions ; the confusion of 

 what any part of the plant is with what it does. 



But I am anticipating somewhat. Before I can pro- 

 perly develop the foregoing ideas, we must trace the onward 

 progress of morphology since the time of Goethe. 



As I have already indicated, the period immediately 

 succeeding the publication of Goethe's VersucJi, up to 

 nearly the middle of the present century, was one fruitful 

 in little else than wild theorising ; it was the period of the 

 so-called " natural philosophers ". This fortunately cul- 

 minated in a reaction to investigation and induction. On 

 a sudden, as it were, a band of men arose, of brilliant ability 

 and indefatigable industry, whose great achievements have 

 revolutionised not only the department of morphology, but 

 the other branches of Botany as well ; I need only mention 

 the names of Schleiden, von Mohl, Naegeli, Hofmeister, 

 Robert Brown, Irmisch, Hanstein, Alex. Braun. It would 

 take me too long to give you anything like a detailed 

 account of their researches ; to do so would be to write at 

 length one of the most important and striking chapters in 

 the history of Botany. All that I can hope to do is to lay 

 before you some of the results of this remarkable renascence 

 of our science. 



I need hardly say that the morphological distinction of 

 the three chief members of the plant as established by 

 Wolff, root, stem, leaf, has been fully confirmed, and has 

 been crystallised in the abstract terms caulome and phyllome x 

 for stem and leaf; the similar terms trichome and thallome 

 being added to designate, the former the epidermal mem- 

 bers of the body (hairs, etc.), the latter the undifferentiated 

 body, characteristic of the lower plants, which presents no 

 distinction of the three primary members. Another im- 

 portant result has been the extension of the idea of meta- 



1 Naegeli und Schwendener, Das Mikroskop, 1867. The correlative 

 term rhizome for the root was not introduced, probably because the word 

 was already in use in Botany, being applied to a creeping underground 

 stem. 



