178 THE SAPROLEGNIACEAE 



angium(figs. 5 and 12) ; this precipitate is not left if the spores are completely 

 formed before discharge or if the contents discharge as an undifferentiated 

 mass (figs. 9 and 14). Thaxter notes only the internal formation of the 

 spores and their escape one by one from the sporangium, swarming at 

 once. On the other hand, Petersen states that the spores "emerge in 

 a great vesicle which soon bursts." This is contrary both to Thaxter's 

 observations and to ours. We find that in case the spore mass escapes 

 before the differentiation of the spores the mass is not surrounded by a 

 vesicle but lies naked in the water. IVIinden takes a somewhat inter- 

 mediate position, stating that the spores escape in a bladder which, 

 however, soon bursts so that most of the spores issue directly from the 

 sporangium. He finds the spores to have the form shown in the second 

 swimming stage of the Saprolegniaceae, with the cilia arising from a 

 depression on one side. The scantiness of our material prevented our 

 observing their form with certainty. 



This rare and peculiar plant grows very poorly under laboratory 

 conditions. Attempts were made to cultivate it on all the subtrata on 

 which Achlyas and Saprolegnias ordinarily grow well, as, for example, 

 corn meal agar, termite ants, bits of boiled corn grain, peas and beans, but 

 without successful results. Unsuccessful attempts were also made to grow 

 the fungus on pieces of pine cones and twigs both green and dry. The 

 plant grows slowly in vegetable juices obtained by boiling corn grains 

 or peas, and it was from such cultures and from the original collection 

 that our observations were made. 



For synonomy and other references see Thaxter, as above cited. 



MONOBLEPHARIDACEAE* 



Phycomycetes living in water and saprophytic on plant or animal 

 remains. Mycelium slender, branched, not divided into cells or con- 

 stricted at intervals. Sporangia apical; zoospores with one or two cilia. 

 Oogonia containing only one egg each and opening at maturity to admit 



*We call attention here to the remarkable genus Myriablepharis Thaxter (Bot. Gaz. 20: 

 482, pi. 31, figs. 1-5. 1895). It is of quite uncertain position and Thaxter does not assign it 

 to any family. According to him the zoospores are ciliated all over as in Vaucheria, a con- 

 dition not known in any other fungus. No sexual reproduction has been observed. The 

 plant has been found more recently in Breslau, Germany, by Minden ('12, p. 476) who 

 confirms. Thaxter's observations. He is inclined to think, however, that the remarkable 

 spores are not those of the plant but of a parasitic protozoan, the fungus being a species of 

 Pythium. Lotsy ('07, p. 125) has, apparently without sufficient reason, placed the genus in 

 the Monohlepharidineae. In this place we might also refer to the genus Rheosporanginm Edson 

 (Journ. Agric. Research 4: 279. 1915) which he places in the Saprolegniaceae. We can see no 

 reason why it should not be considered a species of Pythiiim. 



