20 THE SAPROLEGMACEAE 



On coming to rest they round up. In fig. 12 are shown three normal 

 spores and an anomalous double one with four cilia. This is not a case 

 of fusion after emergence, but of imperfect segmentation of the proto- 

 plasm. (See remarks on page 9). 



Cultures on various media gave the following results: 



On corn meal agar. Formed plentiful gemmae, mostly in groups, but no oogonia. 



On boiled butter bean, on white of egg, and on termites. Showed strong growth, a great 



many gemmae, and after some time numerous oogonia. 

 On boiled willow twig. Showed moderate growth and a few oogonia. 

 A culture in pea agar was left outside on the night of January 14, 1917. It was frozen 



solid, but was not killed. 



The following experiments were made to determine the best method 

 of preserving live cultures: 



A culture on a grub was placed in distilled water in the spring of 1917, but when tested the 



following September was found to be dead. 

 A culture on corn meal agar was placed in a vial March 18, 1913, and was found to be dead 



when tested December i, 1913. 



2. Pythiopsis Humphreyana Coker.* Mycologia 6: 292, pi. 148. 1914. 



Plate 2 



Vegetative growth of long, slender, sparingly branched hyphae about 

 Ii-I4[ji thick which are stoutest in the neighborhood of the reproductive 

 bodies, and which after maturity disorganize rather quickly. Sporangia 

 varying in shape from spherical, oval or pyriform to elongated, tapering 

 and irregular forms, discharging by a short or rather long papilla and usu- 

 ally proliferating from below in a cymose manner; spores monoplanetic, 

 pear-shaped and with two cilia, about 8.9[a in diameter on coming 

 to rest. Oogonia generally borne exactly like the sporangia and not 

 to be distinguished from these when young, apical and often in 

 groups by cymose branching, usually spherical with a basal neck, 

 sometimes pear-shaped and rarely longer and more irregular, varying 

 greatly in size, diameter from 33 to 891J1, averaging about 43^1; wall 

 always smooth and unpitted, about i.4;j. thick. Eggs generally one, 

 occasionally two and very rarely four, centric, t diameter from 24 to 

 40iJL, averaging about 30(j., the wall about 2[x thick, not so nearly filling 

 the oogonium as in P. cymosa; antheridia short-clavate, terminating 

 a stalk that usually arises from immediately below the oogonium, but 

 sometimes of more distant origin, or rarely diclinous, one, two or occa- 

 sionally more on every oogonium and generally applied to its top or 

 distal half, with an antheridial tube which reaches and apparently fer- 



*Most of the data given herewith is taken from the original description, and all the 

 drawings except two were published there also. 



tThey were reported as centric in the original description, but we are not now sure of 

 this. Slides fail to show this character clearlv. 



