Arill.VA l(K) 



in .1 . colorala or a papillate one in A. racemosa. It is easily distinguisheil 

 from the typical .1. racemosa by the oogonia bearing short liliint out- 

 growths and by the fewer and larger eggs, which are rarely more than 

 five to an oogonium. As in Isoachlya nnispora the color in the oogonial 

 walls becomes much fainter after repeated culture renewals. Both dictio- 

 and aplanosporangia occur. 



On mushroom grub in distilled water. Showed a great many oogonia (probably li of all) 

 with antheridia arising from the oogonial neck (No. 6 of Nov. 15, 1913). 



On corn meal agar. Growth normal but delicate; oogonia not abundant, eggs maturing or 

 going to pieces; antheridia absent from some oogonia; papillae irregularly produced 

 and (in some oogonia only a few in a group on one side (No. 4 of Feb. 14, 1918). 



Experiment to test best method of preserving live cultures: 

 Culture put in aquarium jar with algae in laboratory on May 17, 191 1. When tested on 

 Septembei 22, 1917, no growth occurred. 



4 Achlya papillosa Humphrey. Trans. Amer. Phil. Soc. 17: 125, pi. 

 20, figs. 99-102. 1892 [1893]. 



We have not found this and its relationship must be considered 

 doubtful. The following is from Humphrey: 



"Hyphae rather slender, long. Zoosporangia sparingly developed, 

 cylindrical, little larger than the hyphae. Oogonia terminal on main 

 threads or on short lateral branches, or sometimes intercalary, oval or 

 ovate, rarely globular, thickly studded with short, blunt, wart-like out- 

 growths of their unpitted walls, often with a marked apiculus. An- 

 theridial branches usually developed with each oogonium, fine and 

 branching, arising near it from the main thread, or rarely from the oogon- 

 ial branch. Antheridia imperfectly formed. Oospores as many as 

 twelve in an oogonium, oftenest four to si.x, centric, their average diam- 

 eter about 25|X. 



Massachusetts — Amherst. 



"This plant, which seems to be sufficiently distinct from previously 

 described species, has been obtained in several cultures, but from only 

 a single source; namely, the very prolific mossy pool in Amherst, already 

 mentioned. It may be recognized by its long hyphae, finer than those 

 of most Achlyae, and its oogonia with warty, rather than spiny, walls, 

 and several oospores in each. I have never seen well-differentiated 

 antheridia or fertilization-tubes, although the ends of the antheridial 

 branches are applied to the oogonia. 



"While bearing no near resemblance to any species heretofore fig- 

 ured, this plant may be somewhat closely related to the next [A. recurva 

 Cornu], if the latter is well founded." 



