90 



JouRiv^AL OF Tilt: Mitchell Society \ September 



each day for 5 or 6 days. By this time an entirely new crop of eggs 

 had formed and were ready for discharge. They were collected 

 upon slides and shells as before. The spores germinated abundantly 

 in each case, but from the second lot none survived longer than two 

 weeks, while there were a goodly number of sporelings 5 to 10 mm. 

 long upon the first lot of shells when the experiment was discon- 

 tinued about six weeks later. The latter are clearly fertilized eggs 

 capable of growth into tetrasporic plants under normal conditions, 

 while the former were unfertilized eggs which divided and formed a 

 cell body consisting of as many as 50 cells in some cases, but all of 

 which without exception eventually perished. 



This rather remarkable power of the fertilized eggs to cling to the 

 parent plants, probably within the oogonia, for such long periods 

 proved a very confusing fact tlnv^ugli all the experiments dealing 

 with eggs. 



Tables 2 and 5, giving the results when the cultures are obtained 

 from male and female plants placed together in an aquarium in quiet 

 water show essentially the same results as the unfertilized eggs and 

 control cultures, except that the proportion of tetrasporic plants is a 

 trifle greater than in either of the other cases, due in all probability 

 to the occasional fertilization of eggs by the very few sperms liberated 

 under these conditions. The plants found on these shells, then, with 

 the exception of the excess of tetrasporic plants, are also the result of 

 chance spores. The following summary may be compared with those 

 given for unfertilized eggs and controls. 



