274 H. MAESHALL WAED. 



plasm into tlie oospheres (Achlya and some Sapro- 

 legnias) and the extreme parthogenetic forms of Saprolegnia 

 where no antheridia are formed at all, there exist cases where 

 the antheridia apply themselves to the outside of the oogonia, 

 but either form no antheridial tubes at all or only 

 rudimentary ones (S. torulosa, S. asterophora). These 

 facts may also be diagrammatically represented as follows. 



Parthenogenetic 

 forms of Saprolegnia 



S. torulosa, S. Asterophora 



Achlya, Typical 

 Saprolegnia 



Peronosporese. 



If now the various cases are duly considered, De Bary thinks 

 that we may probably regard the Peronosporese as phylo- 

 genetically important in two senses : 



1. Their general biology strongly suggests that they are 

 derived from Algal ancestors, possibly not very unlike V au- 

 di eri a and its allies. 



2. That they are the progenitors (or the near relations of 

 progenitors) of a few chief series of true Fungi — on the one 

 hand the main series of Ascomycetes and allies; on the 

 other the Saprolegniae and forms derived from them, and 

 allied to them. 



If we now regard these forms more closely, it is not difficult 

 to agree with many of De Bary's conclusions. It will be clear, 

 in fact, that some of them are not new, though they are stated 

 in a much clearer form than by Brefeld and others Avho have 

 helped to systematise the chief groups already. We will first 

 shortly consider the main subdivisions themselves. 



The Zygomycetes are regarded as branching oflF from the 

 Peronosporese. In this group De Bary arranges the Mu- 



