86 PHYCOMYCETEAE 



study. Emerson (1938) demonstrated another type of reproduction in 

 several species which he placed in the section Cystogenes. This has been 

 studied by McCranie upon whose observations the following life cycle is 

 based. In A. cystogenus Emerson the sporophyte is as in section Euallo- 

 myces, except that the resting sporangia remain attached to the sporo- 

 phyte in the latter and are deciduous in the former. Emerson reported 

 that on germination of these resting sporangia, there emerged large 

 posteriorly biflagellate swarm cells which quickly encysted and then gave 

 rise to four posteriorly uniflagellate swarmers from each cyst. These pro- 

 duced the sporophytic generation. McCranie's description differs from 

 that of Emerson in that he reports the emergence of nonflagellate, some- 

 what amoeboid, spores from the resting sporangium. These encyst and 

 within them are formed four uniflagellate gametes equal in size, which 

 unite to form posteriorly biflagellate zygotes from which develop the 

 sporophytes. The fact that in Blastocladiella cyslogena Couch and Whiffen 

 the swarmers emerging from the cysts act as isogamous gametes would 

 seem to make McCranie's conclusions as to the sexual processes in 

 A. cystogenus nearer the truth than Emerson's. The resting sporangia of 

 Allomyces are able to survive in the dry state many months or even years. 

 The species of the genus are more often found in the warmer parts of the 

 world, such as the southern United States, Mexico, Central and South 

 America, West Indies, Southern Asia, East Indies, Africa, and southern 

 Europe. (Fig. 25.) 



Order Monoblepharidales. The chief differences between this order 

 and the Blastocladiales are the fertilization of large, nonmotile eggs by 

 posteriorly uniflagellate sperms; the hypha-like mycelium, like that of 

 Allomyces but lacking the perforated pseudosepta of that genus; the 

 absence of thick-walled resting sporangia and of alternation of genera- 

 tions, with minor differences in the structure of the swarm cells. Of the 

 three genera here included in this order sexual reproduction is unknown 

 in Gonapodya and the correctness of the inclusion of that genus in the 

 order is doubtful. Possibly it should be placed in the foregoing order. 

 The two other genera, Monoblepharis and Monohlepharella, are closely 

 related. With the doubtful inclusion of Gonapodya but one family is 

 recognized. The genus Myrioblepharis has been placed in this order by 

 some investigators, but it is probable that this is not an independent 

 organism but some other aquatic fungus parasitized by a ciliate Pro- 

 tozoan. The only species, M. paradoxa, was described by Thaxter in 

 1895, and found once by von Minden in 1915. The papers of these authors 

 should be referred to. 



Family Monoblepharidaceae. Gonapodya is a genus of two species, 

 growing saprophytically on vegetable matter in fresh water. When rose 

 fruits are placed in water for several weeks, this fungus frequently de- 



