ISOACHLVA 85 



III equal parts of .05'^^ haemoglobin solution, .25% NalliPO., and .25% KjPOi on fly. 

 Growth slender, a fair number of oogonial initials, tew antheridia. Upon transferring 

 the culture to pure water many sporangia were formed, and a good many oogonia with 

 eggs and with antheridia attached to them. 



In equal parts of .05% haemoglobin, .25% NaHjPOi, .25% K,PO., and .25% Ca,(PO,)., 

 growth vigorous, many oogonia (but few with eggs) and many antheridial branches, 

 but only a few applied to oogonia. In this culture many hyphae gave rise to numerous 

 antheridial branches all along the hypha from the base almost to the tip. Many of 

 these resembled branched and tortuous root hairs. The culture transferred to pure 

 water and left standing for a few days and then examined. It contained many oogonia 

 with eggs and many empty sporangia and gemmae. The antheridial branches had 

 disappeared. 



On piece of boiled corn grain cut from the germ but also having some of the hard and soft 

 endosperm of grain. Growth vigorous, sporangia produced in fair number during 

 youth of culture and all of them emptying. Oogonia produced in great abundance, 

 var>ing much in size and shape and in the number of eggs. Antheridia very scarce, 

 only 2 oogonia with antheridia having been seen in the whole culture. In cases 

 where antheridia were seen antheridial tubes were developed. 



On piece of boiled corn grain cut from the germ. Growth vigorous, a fair number of spor- 

 angia present. Oogonia produced in great abundance, varying considerably in shape 

 from spherical to cylindrical. Antheridia almost totally absent, only one oogonium 

 with antheridium having been seen. 



On corn meal agar, growth fairly rapid, vigorous, co\-ering the agar in petri dish in about 

 two days. No sporangia. Oogonia produced in great abundance, a large majority 

 of them containing perfectly formed eggs. About 5% of oogonia with antheridia. 

 Some of the oogonia very irregular in shape. 



2. Isoachlya unispora Coker & Couch n. sp. 



Plates 22 an'd 23 



Mycelium vigorous, more e.\tensive than in most species of Sapro- 

 legnia; hyphae irregular, not straight or cylindrical, normally little 

 branched, about io-35;a thick, and usually largest toward the periphery; 

 sporangia typically scarce, frequently almost none, often quite irregular; 

 primary ones elongated, varying from sub-cylindrical and slightly if at 

 all thicker than the hyphae to shorter, thicker, and more flask-shaped; 

 secondary sporangia arising by cymose branching, and also not rarely 

 growing through the empty ones, but in such cases the new sporangia 

 forming entirely outside the mouth of the old ones; spores diplanetic, 

 9-3~i3-7;j-- most about io.5-ii.5,a thick at rest; emptying as in Sapro- 

 legnia and swimming rather sluggishly and aimlessly, some coming 

 quickly to rest: on emerging from the cysts they swim longer and more 

 actively. Xot rarely the spores remain in the sporangia and sprout 

 there as in most other species at times. Gemmae plentiful or few, 

 typically spherical, with or without a neck, usually in chains, the distal 

 member of which is not rarely an oogonium; emptying on changed con- 

 ditions by an elongated papilla. Oogonia abundant, mostly spherical, 

 rarely pyriform, usually with a distinct neck and borne on lateral branches, 

 quite often terminal on small hyphae, and in strong cultures frequently 

 in flusters, with the arrangement of a scorpioid cyme, not rarely inter- 



