MONOBLEPHARI DALES 139 



various authorities. Fischer (1892: 378) made it the basis of 

 a new genus, Gonapodya, and this genus and Monohlepharis make 

 up the Monoblepharidineae of his classification and that of 

 Schroter (1893: 106). The statement by Cornu that spermato- 

 zoids occur in M. prolifera has never been verified by any other 

 worker, and Thaxter (1895: 478) suggests that Cornu may have 

 been misled as to their presence by the great variation in size 

 exhibited by the zoospores in some instances. He feels, more- 

 over, that Cornu's "oospores" may have been merely encysted 

 sporangia. The mycelium of Gonapodya differs very strikingly 

 from that of Monohlepharis, in being constricted as in the Lepto- 

 mitaceae, and in most of the recent classifications (Thaxter, 

 1895: 478; v. Minden, 1912: 576) the genus is included in that 

 family. Here it is incorporated instead in the Blastocladiaceae 

 (p. 134) on account of its uniciliate zoospores and non-cellulose 

 cell walls. Laibach (1927), has recently studied both Mono- 

 hlepharis and Gonapodya in stained preparations and, impressed 

 by the similarity of nuclei and cytoplasmic vacuolation in the 

 two genera, advocates the incorporation of Gonapodya in the 

 Monoblepharidales on cytological bases. 



Following the establishment of the genus Monohlepharis by 

 Cornu a period of twenty-five years elapsed before any member 

 of the genus was seen again, some workers coming to doubt the 

 very existence of a genus having the unique characters which 

 he figured and described. However, in 1895, Thaxter described 

 two new species from America, his account corroborating the 

 essentials of Cornu's description. Subsequently, other species 

 have been observed by Thaxter (1903) in America, and by Lager- 

 heim (1900), Woronin (1904), von Minden (1911), and Laibach 

 (1926; 1927) in Europe. 



The order is the smallest in the fungi, and as here treated con- 

 sists of the family Monoblepharidaceae containing the single 

 genus, Monohlepharis. 



The mycelium of Monohlepharis is saprophytic, occurring 

 usually in decaying twigs lying in the water. It is coenocytic 

 and characteristic in aspect. The cytoplasm forms a network of 

 meshes which are regular in size and form, a strikingly uniform 

 vacuolation resulting. The strands of protoplasm tend to cross 

 the hyphae at right angles rather than to run longitudinally as 

 in the Saprolegniales. The fertile hyphae arise from a branching 

 vegetative mycelium which is fixed to the substratum by rhizoids. 



