I06 THE SAPROLEGNIACEAE 



Oogonia abundant, the majority with antheridial cells and tubes. A good many, not 



over 2%, with outside antheridia. 

 In .1% K.SO1. Vigorous growth. Very few sporangia. Many oogonia, nearly all with 



antheridial cells and tubes and at least 5% with extra outside antheridia. 

 In .1% Ca3(P04)5. Rather sparse growth. Very many sporangia. Many oogonia, a 



good many extending into the threads, which also contained eggs. Antheridial cell 



cut off in most cases, and tube formed. Not more than i or 2% of outside extra 



antheridia. 

 In .1% KsPOi. Growth moderate. No sporangia. Many oogonia, nearly all failing to 



mature eggs. Antheridia cut off on only a small number. 



The following two experiments were made to test the best method 

 of preserving live cultures: 

 Culture from No. 2 of September 10, 1912, put in vial on corn meal agar on March 18, 191,^. 



Found to be dead when tested on December I, 1913. 

 Culture on corn meal agar put in vial of water which was then closed with a plug of cotton 



and put in a dark place in May, 1913. Test for life was made with a mushroom grub 



in December, 1913, and new growth resulted. The eggs, however, were nearly all 



dead and disorganized. Scarcely one in 100 was alive. 



2. Achlya racemosa Hildebrand. Jahrb. f. wiss. Bot. 6:249, pi. 15. 1867. 

 ? Achlya lignicola Hildb. Jahrb. f. wiss. Bot. 6: 255, pi. 16, figs. 

 i-6a. 1867. 



Plates 14 and 31 



Hyphae stout, usually 25-361J. thick at base. Sporangia long, almost 

 cylindrical, rounded or tapering at the tips, about the size of the hyphae 

 bearing them or sometimes slightly larger, sometimes twisted like a cork- 

 screw. Spores 9-1 i[x in diameter; on emerging forming an irregular 

 cluster or imperfect sphere which slowly expands as if embedded in 

 jelly so that the spores become more or less separated singly or in groups. 

 Gemmae usually few, formed by the distal parts of hyphae becoming 

 divided into joints after being densely filled with protoplasm. Oogonia 

 racemosely borne on short lateral branches, rarely intercalary, plentifully 

 developed in all cultures, rather small, 40-701^ in diameter; wall dis- 

 tinctly yellowish at maturity, smooth and unpitted except where anther- 

 idia touch. Eggs variable in size, 16.6-27.7(1 in diameter, most about 

 22[x, centric, 1-8 in an oogonium (Humphrey says i-io), in most cases 

 2-5, centric, the wall thick (about 3.511). Antheridial branches short, arising 

 from oogonial branches near the basal walls of the oogonia, or as often 

 from the neck-shaped base of the oogonium or even from its curved 

 surface, rarely from the main hyphae. Antheridia one or two, some- 

 times more, to each oogonium; short-clavate, usually bent and applied 

 by their tips to the oogonia. 



