202 Morphology and Systematic Botany iinder [BOOK i. 



theory of original types. The assumption that every natural 

 group represents an idea was here quite out of place ; the 

 notion entertained up to that time of what was really meant by 

 the natural system had to be entirely altered ; it could as little 

 pass for a body of Platonic ideas as for a mere framework of 

 conceptions. But the effect of the work was great in respect 

 to the system also ; the Cryptogams were now the most 

 important objects in the study of morphology ; the Muscineae 

 were the standard by which the lower Cryptogams must be 

 tried, the Ferns were the measure for the Phanerogams. 

 Embryology was the thread which guided the observer through 

 the labyrinth of comparative and genetic morphology ; meta- 

 morphosis now received its true meaning, when every organ 

 could be referred back to its parent-form, the staminal and 

 carpellary leaves of the Phanerogams, for example, to the 

 spore-bearing leaves of the Vascular Cryptogams. That 

 which Hackel, after the appearance of Darwin's book, called 

 the phylogenetic method, Hofmeister had long before actually 

 carried out, and with magnificent success. When Darwin's 

 theory was given to the world eight years after Hofmeister's 

 investigations, the relations of affinity between the great divi- 

 sions of the vegetable kingdom were so well established and so 

 patent, that the theory of descent had only to accept what 

 genetic morphology had actually brought to view. 



So gorgeous a picture as Hofmeister had designed of the 

 genetic connection of the vegetable kingdom, except the 

 Thallophytes, could not possibly be completely perfect and 

 correct in all its separate features ; there were still many gaps 

 to fill up and particular observations to correct. Hofmeister 

 himself continued his labours ; the remarkable genera 

 Isoetes and Botrychium were in the following years more 

 carefully studied by himself, the fertilisation and embryology 

 of the Equisetaceae by himself and Milde, and those of 

 Ophioglossum by Mettenius, and all were fitted into their place 

 in the system. To the present day it is always a profitable 



