— 434 - 



attack is deadly. This fungus does not produce so many zoospores as 

 the Leptolegnia, and the intensity of the disease is thereby less violent. 

 Bosniina seems to be attacked in years where the Daphnije are few in 

 number. Resting spores are produced in considerable number during the 

 whole period of the fungus. 



In the systematical part I mention the submerse Phycomycetes I have 

 found while investigating parts of Sealand and Jutland. Referring to my Danish 

 paper 1 shall here only mention the new facts and my critical remarks. 



Saprolegnia. Nees v. Esenbeck. 



In a short introduction I make mention of the experiments of Klebs 

 with Saprolegnia mixta, of other botanists and of my own on account 

 of these experiments of Klebs. My own experiments, the results of which 

 I will publish later, accord with certain of Kaut!mann's. Certain species 

 easily form resting spores, others with great difficulty. The species for- 

 ming in the same place gemmae and parthenospores, as Saprolegnia Thu- 

 reti, are, according to my own experience, in particular inclined to form 

 resting spores, while other forms with separate formation of sexual or- 

 gans and gemmae, as Achlya racemosa, with difficulty form resting spores 

 under artificial conditions. 



2. S. semidioica sp. nov., cf. diagnosis page 378. 



3. S. monoica (Pringsheim) de Bary. 



To this species I have referred individuals the characters of which, owing 

 to the presence of antheridial tubes, were approaching to those of Saprol. 

 mixta. 1 am uncertain in which way this form is to be distinguished from 

 Sapr. monoica. I cannot attach any importance to the number of pores. 

 This character is perhaps as variable as the number of the antheridial tubes. 



4. S. paradoxa cf. diagnosis page 379. 



8. Leptolegnia caudata de Bary. 



This species is found in a single locality in Sealand and in the Fure 

 Sa, where it appears as parasite in Leptodora hyalina. 



I shall here supply my earlier remarks concerning this species. 



In the Leptodora the mycelium is especially characterized by right 

 branch-angles. When the Leptodora is fully interweaved by the mycelium, 

 the formation of the zoospores takes place. The whole protoplasm of 

 the fungus can be swallowed up by the formation of the zoospores, which 

 are formed in great number. The zoospores come out hooked together 

 by the flagella. Fig. II b, c, d and e show the form-changes of the 

 zoospores after the coming out. 



