WINGE, CYTOLOG. STUDIES IX THE PLASMODIOPHORACEx^. 27 



Rhizomyxa hypograea Borzi.^- In this species which 

 is somewhat closer related to the Plasmodiophoraceae.. the 

 naked plasma situated in the host-cell changes directly into 

 a sporosorus, as the rather large spores at the maturity set 

 free 1 — 2, rarely a greater number of uniciliate zoospores. 



By a direct transformation of the whole plasma resting- 

 cysts are, however, sometimes formed consisting of numerous, 

 close lying small resting-spores which at the germination are 

 converted into as many small zoosporangia. The possibility 

 is moreover not precluded that this species, like the two 

 first named, may form large ephemeral zoosporangia. 



Wo ron i na poly cyst is Cornu^^ is evidently-closely 

 related to Bhizomyxa, as the naked plasma in this species is 

 likewise converted either into a sporosorus in which the 

 spores at maturity send out several swarming-spores or into 

 almost globular, brownish resting-cysts formed by many small, 

 close lying spores which at the germination send out swarming- 

 spores of the same appearance as those which originate from 

 the above named larger spores. The zoospores are biciliate 

 as they have one lateral and one apical ciha. 



Pyniiosorus mariuus Juel.^^ 



This fungus is plainly very closely related to the Plas- 

 modiaphoraceae. Juel found it growing on dead branches 

 of Cystodonium 2^?(rp2rrof.sce7i5 which he had cultivated in 

 his laboratorium. He examined the fungus as well in live 

 condition as after he had fixed it and cut it on the micro- 

 tome. He gives (1. c.) a detailed and excellent description 

 of the developmental cycle of the fungus which is of 

 special interest, as it seems to throw some light on the 

 Plasmadiophoraceae. First shall be mentioned that Juel 

 considers himself justified in stating that the fungus is not 

 a parasite, but a saprophyte, for he only found it an dead 

 branches and sometimes placed on the surface (?) of the alga. 

 There is, however, scarcely any doubt that Pyrrliosonis like 

 its nearest relations is parasitic — at least during part of 

 its life. It also seems to me that Juei/s figures of the inter- 

 cellular growth of the fungus point in this direction. — He 

 finds the life-c^^cle of the fungus to be as follows. Small 



