126 THE SAPROLEGXIACEAE 



On corn meal egg yolk agar. Grew vigorously but did not cover dish. A pretty dense 

 growth of aerial hyphae was formed and reached the lid — looked much like Mncor. 

 No reproduction. 



In the following five experiments equal parts of a .2% solution 

 in distilled water of the salts indicated was used ; the food material being 

 yolk of egg : 



In KHiPOt. Stout, healthy growth. No reproduction. 

 In NaHzPOi. Good growth. No reproduction. 



In K2SOJ. Poor growth. No reproduction. Hyphae incrusted with amorphous granules. 

 In Ca3(P0i)j. Strong, vigorous growth. No reproduction. 



In Ca(N03)2. Strong but limited growth. A good many sporangia, some emptying nor- 

 mally, most with spores sprouting in position. 



The six following cultures were made from No. 12 of INIarch 6, 



1913: 



On egg yolk in distilled water + i drop of lactic acid to 100 c.c. Growth very strong and 

 healthy, consisting of large and little branched hyphae. Sporangia sparingly produced, 

 long and pointed, discharging in most cases. Spores sprouting in position in some 

 cases. No other reproduction. No noticeable bacteria. 



On egg yolk in distilled water + i drop of lactic acid in 200 c.c. Growth as in the preced- 

 ing experiment, except not quite so strong and no sporangia or any other reproduction. 

 No noticeable bacteria. 



On boiled potato tuber and sprout in potato broth. No growth. 



On boiled potato tuber and sprout in distilled water. Fair growth of limited extent, bac- 

 teria present and apparently interfering. Tips of hyphae often dying and the thread 

 extended by growth from below, as is frequent in this species. No sporangia or other 

 reproduction. 



On egg yolk in distilled water. Growth fairly good, but no sporangia or other reproduction. 

 Not foul with bacteria. 



On egg yolk in 3% cane sugar in distilled water. Growth strong, somewhat contorted, 

 only a few sporangia, and spores sprouting at the tip. 



The following experiment was made to test the resistance to cold : 



A strong culture was left outside on window sill and was frozen hard (temperature 23 F.). 

 The culture was killed. 



The following experiments were made to test the best method of 

 preserving live cultures : 



A culture (No. 6 of April 19, 1913) put in vial on corn meal agar in the spring of 1913 was 

 found to be dead December I, 1913. 



Pure culture (No. 4 of November 25th, 1912) was put in an aquarium jar with algae on 

 laboratory table on February 19, 1913. No growth resulted when tested on Septem- 

 ber 18, 1917. 



The following experiment is typical of many made to determine the 

 effect of cold on the formation of reproductive organs: 



On piece of boiled corn grain in sterile well water in ice box temperature from 12° to 20° 

 C. Growth good and many normal oogonia formed, but only about a fifth as many 

 as in the var. proUfica in the same circumstances; no sporangia. 



