INTRODUCTION 37 



reproductive organs have ever been formed under these circumstances. 

 Gonapodya, although more troublesome than Monoblepharella, can be 

 readily cultivated on glucose-yeast (Emerson, 1950, and R. M. Johns, 

 comm.). One would expect published records of the cultivation of 

 Monoblepharis to be numerous, because of its relatively profuse myce- 

 lial growth. They seem confined, 1 however, to those of Emerson (1950), 

 who reports the growth of M. polymorpha and M. sphaerica in pure 

 culture on agar containing 0.5 per cent tryptone. 



Of the few known members of the Hyphochytriales, only three have 

 been cultivated, namely, Rhizicliomyces apophysatus by Whiffen (1941b), 

 R. bivellatus by Nabel (1939), and Hyphochytrium catenoides by Karling 

 (1939b) and others. 



Save for Couch's (1939a) account of obtaining pure two-membered 2 

 cultures of Woronina polycystis, none of the endophytic obligate para- 

 sites of the Plasmodiophorales has been recorded in cultivation. 



Of the Leptomitales, Minden (1916) records the growth of Rhipidium 

 interruption in dextrose and peptone solutions, malt gelatin, and the 

 like. Minden cultured Araiospora spinosa on plum-decoction gelatin 

 and in malt and bouillon broth, but not until recently has his feat been 

 duplicated, despite repeated attempts (see Kanouse, 1927). Thus, Emer- 

 son (1950) records the successful cultivation of Rhipidium americanum 

 on glucose-yeast medium. Species of Leptomitus (Schade, 1940; Schade 

 and Thimann, 1940), Apodacldya (Gilpin, 1954), and Sapromyces 

 (Bishop, 1940; Emerson, 1950) have all been obtained in pure culture. 



Few of the Lagenidiales have been brought into culture. Lagenidium 

 giganteum, however, has been grown bacteria-free on various labora- 

 tory media by Couch (1935b) as has also a species of Myzocytium by 

 this same investigator (1939a). A species of Sirolpidium, parasitic on 

 marine clams, has been grown in culture by Vishniac (1955b). 



Although the higher members of the Saprolegniales 3 have nearly 

 all been cultured, the minuteness and the simple nature of the thalli 

 in the Ectrogellaceae and the Thraustochytriaceae make them exceed- 



1 Perrott (comm.) reports growing certain larger species in pure agar cultures. 



2 That is, the host with its endophytic parasite. Two-membered cultures have 

 also been reported by Emerson (1950) for the chytrids Rozella achlyae and R. 

 allomycis. 



3 See Goldie-Smith (1956b) on maintenance of stock cultures. 



