— 432 — 



reduced higher Phycomyeetes. Admitting that, and not seing a connec- 

 tion between the Monadinse and the Chytridineae, it must be correcter 

 also to consider the uniflagellated Olpidiaceae, in all morphological re- 

 spects resembling the two-flagellated Pseudolpidiaceae, as reduced higher 

 Phycomyeetes or other higher forms, probably Algae. As the intermediate 

 forms between these and the Olpidiacese must for example the rhizoid- 

 bearing Rhizidiaceae be considered^ particularly such forms as Entophlyctis 

 heliomorpha og Rhizidium tetrasporum Sorok., where the rhizoids are not 

 much developed. That further such rhizoid-bearing forms can be derived 

 from myceliated forms is probable when we consider the insensible transi- 

 tion between mycelium and rhizoids e. g. in Siphonaria. The hypotheti- 

 cal ancestors of these uniflagellated forms are probably Monoblepharidine^e, 

 but probably also, we must suppose, Algse. 



In the two flagellated series Sirolpidium for example can be 

 considered as intermediate forms between Pseudolpidium and Lagenidium. 

 In Sirolpidium the thallus is divided in zoosporangia which disunite into 

 Olpidium-shaped fragments. 



I refer here to my system of Phycomyeetes (page 356). Maintaining 

 the division of this group in two series as indicated by Lotsy and Vuille- 

 min, I assent to the point of view of de Bary thinking that the Ghytridi- 

 nese on the whole should be derived from higher Phycomyeetes or Algae, 

 and that the Phycomyeetes are not in relationship to the Monudinae. 



In the survey pp. 356 — 358 I mention two new genera Bicilium and 

 Oligostomum. The first genus shall comprise all Pleotraehelus forms with 

 two flagella (for the present only one species Bicilium Andreei = Pleotra- 

 ehelus Andreei Lagerh.) ; the other genus shall comprise such (uniflagellated) 

 Olpidiaceae, which only have one to three channels for the zoospores, for 

 example Oligistomum Rosenvingii = Pleotraehelus Rosenvingii mihi. 



In the following chapter I communicate biological remarks on the 

 submerse Phycomyeetes mentioning their occurrence in Nature. Some of 

 those have general interest and they should be mentioned here. The 

 hyphae-bearing submerse Phycomyeetes may occur in all localities where 

 the water is tranquil not containing much ferric oxide and not of short 

 duration. The most used substrata are branches of several trees. Their 

 growing must be checked by dense vegetation or by certain lower animals 

 for example of larvae of Phryganeag. They generally winter by their 

 spores but I have several times found living mycelium and gemmae of 

 Saprolegniaceae in the frostless periods what indicates that these fungi 

 can winter in a vegetative stage. Drying up the mycelium cannot sup- 

 port. The most frequent are Achlya racemosa and Saprolegnia Thureti. 



The Chytridineae occur also in tranquil water and are commonly 

 spread. The most frequent are : Rhizoph. poUinis , the forms on the 



