ACHLYA 117 



the Chapel Hill plants in no way (.'xcept for the short stalked oogonia, 

 more numerous eggs, and more branched antheridial branches. Again 

 found in some material collected at Fayetteville, N. C, July 10, 1920 

 (Miss Holland, coll.). Distinguished from all other members of its grouj) 

 except .1. aplaues by the decidedly larger eggs, and even in the latter 

 species the eggs do not a\erage so large and the anther id ia are always 

 diclinous. Ward's figures 1-14, plate 22 (1883), while labelled.!. />6i/3'a;/(/m 

 deB., look more like the present species. 



This is the plant treated by us as A. deBaryana in Mycologia 4: 

 319, pi. 78, 1912, but we now think it cannot be that species. The un- 

 pitted walls of the oogonia together with the always (practically) androg- 

 ynous antheridia that arise near the oogonia of the latter must exclude 

 our plant. 



The antheridial branches of .4 . flagellata are unlike all others we ha\e 

 seen: only A. proliferoides may have them so intricately branched and 

 such branching is not so common even in that species; neither are they 

 so complex in .4. imperfecta (No. i of July 20, 1918), though often long 

 and complex in that species; furthermore the short and simple androg- 

 ynous branches of A. americana and at times of A. imperfecta are not 

 present in ,4. fiageUata; and the antheridial branches often arise from 

 the stalks of the oogonia in A. imperfecta and never in this. The oogonia 

 are much inclined to proliferate and empty their contents into a new 

 one by an outgrowth, as is true in all members of the group, and in this 

 species this often leads to sac-like shapes, with or without a constriction 

 (pi. 37, fig. 11) or to other unusual forms (as said above a few papillate 

 projections are to be seen rarely). Oogonial initials may halt after reach- 

 ing full size and become gemmae, or their stalks may become part of 

 a gemma when the main hyphae are segmented. It is also quite easy 

 to find oogonial stalks that are branched at right angles below with a 

 secondary oogonium on the branch, as in A. caroliniana, and all the other 

 members of this group that we ha\e seen. 



In regard to the pits we have here the usual uncertainty of the group. 

 Without apparent cause a group of oogonia here and there may show 

 them plainly, either one or many, while the great majority in the same 

 culture, as, e.g., on a corn grain or a mushroom grub, may have none 

 except for the easily seen thin places under the antheridia. The pits 

 are never so large and conspicuous as in /I. conspicua or in the Ferax 

 group of Saproleguia. \\'hen grown on nutrient agar the sporangia 

 may open and discharge their spores inside the agar. In such case the 

 spores do not make a sphere at the tip, but flow back and form a layer 

 around it (fig. 12). The species is subject, though rarely, to the attacks 

 of an Olpidiopsis. 



