n8 Morphology 



separating th - :rom the rest : a third division 



the E::ibry:phyta Zoidiogania. or Archegoniatae 

 included Eichlers Bryophyta and Pteridophyta, and a 

 fourth the Einbryophyta Siphonogama comprised the 

 Phanc. g -. wMch he arranged in two subdivisions, each 



-ordinate with Bryophyta and Pteridophyta viz. the 

 amae and the Angiospermae. 



Though Engler '- - - rm was adopted largely on the 

 continent of Europe, it did not at first obtain acceptance 

 in England, where Eichler's main divisions were adhered 

 to up to the end of the century. 



The acceptance of these four main groups and the 

 discussion of their relationship to each other directed 

 inquiry into the question of phylogeny. which gradually 

 .lined a grr..: importance in the literature of the period, 

 and maintain-, life interest throughout the closing years of 

 the century. The inquiry received considerable support 

 from the renewed ac:: : .at was displayed in the in- 

 ve?~ _ : tt I sol remains : i plants from the different 



geological strata, interest perhaps being - ~t in the 

 question of the origin of the Phanerogamic Flora. To 

 this branch of study reference will be made in a later 



.pter. 



The difficult}' of tracir .. descent of the Brvophyta 



from the _."._ si -.-nized by all. As we have seen. 



it ass - rominence in connexion with the dis- 



cussion c: mologous and ar::::.r::c theories of altern- 



ation of generations, and while no writer claimed to have 

 solved the proKr:.. there was a general . :.-.ent that 

 the explanation must be looked for in connexion with 

 the migration of plan:- : ::i an aquatic to a terrestrial 

 environment, and the consequent upsetting of their physio- 

 logical equilibrium. That it was due to some far reaching 

 cav.- - bvious, when the course of evolution in the 

 of the . _ s -:udied and compared with that 



