30 



THE SAPROLEGNIACEAE 



calary oogonia, diclinous, of various shapes from clavate to clasping 

 or irregular, often curving part way round the oogonium, and borne 

 on slender antheridial branches; usually more than one on an oogonium. 

 "This species seems to differ decidedly from all others described, 

 especially in the large, thin-walled oogonia without pits. Rarely two 

 oogonia were observed in series. This species may be related to S. 

 anisospora, of which species little is known, though no evidence of two 

 kinds of zoospores was found in the present species. Besides its marked 

 morphological characters, 5. Kauffmaniana is interesting from the fact 

 that it is especially sensitive to the concentration of haemoglobin. Oogo- 

 nia were but sparingly produced on flies, many cultures having none, 

 and no culture having more than a few. Tests were made by trans- 

 ferring vigorous mycelium to haemoglobin solution, and it was found 

 that only where the haemoglobin had a concentration of 0.025 per cent 

 were oogonia formed." 



3. Saprolegnia delica n. sp. 



Plates 5 and 6. 



Growth delicate and lax, but uniform and symmetrical, the hyphae 

 straight and simple at first, then much branched. Sporangia long, 

 nearly cylindrical or later irregular, abundant and symmetrical in most 

 young cultures, the later ones often irregularly inflated or bent, repeat- 

 edly proliferating from within, and not rarely laterally from below; 

 spores about 10.5-11.551, in diameter; gemmae plentiful or few (not nearly 

 so abundant as in 5. diclina), spherical or pyriform to fusiform or clavate, 

 often in moniliform chains; oogonia typically spherical, abundant on 

 most media, terminating the main branches and also racemosely borne 

 throughout on rather long or rarely short lateral branches that are usually 

 two or more times as long as the diameter of the oogonia; wall smooth, 

 colorless, thin, about i.8;j. thick, furnished with rather few pits about 

 3-7~8.5:j. in diameter which are not nearly so conspicuous as in 5. monoica, 

 S. mixta or S. ferax; diameter of oogonia on termites about 40-63;!., 

 averaging about 55ti., on fly 42-yO[L, averaging about 60[i; eggs mostly 

 1-6, often 8, and very rarely up to 16 (in abnormal cases when large 

 oogonia are filled with very small eggs there may be up to 40), centric, 

 quite dark when young (in transmitted light), lighter at full maturity, 

 averaging about 25-2711, with extremes of 14.8-33;!., the smallest often in 

 oogonia of normal size and not rarely mixed with the larger. Antheridial 

 branches abundant, often long and rambling, the larger part diclinous, 

 rather stout and persistent; antheridia present and usually numerous 

 on nearly all or all oogonia (95-100%), each oogonium typically furnished 

 with at least one diclinous antheridium, and at times with androgy- 

 nous ones also, occasionally absent from oogonia that terminate long 

 branches and are therefore removed some distance from the main mass; 

 pear-shaped or irregularly tuber-shaped, well filled with protoplasm; 

 antheridial tubes present and not inconspicuous. 



A very common species, appearing in marsh at foot of Lone Pine 

 hill, edge of pond on Glen Burnie farm, brook behind athletic field, 



