218 BOTANICAL GAZETTE [MARCHE 
removed, the pots were set aside and neglected for about two weeks. At 
the end of this time, the surface of the soil was brown, and all the prothallia 
appeared dead. The pots were then kept moist under bell jars in weakened 
light. After a period varying from six to eight weeks, many of the old 
prothallia had developed adventitious outgrowths. Some of these out- 
growths were filaments or irregularly shaped prothallia covered with 
antheridia. Others developed into elongated prothallia bearing archegonia, 
which in turn frequently became monoecious by developing adventitious 
shoots bearing antheridia. 
Germination began in the sterilized water cultures four days after the 
spores were sown. Six days later the prothallia had attained a growth of 
ten cells. A set of cultures was then made, by transferring 100 prothallia 
to each of several nutritive solutions. For each of these sets a control set 
was kept in sterilized distilled water. Six weeks after the prothallia had 
been transferred to the nutritive solutions, male prothallia bearing anther- 
idia and female prothallia bearing archegonia were observed in about equal 
proportions. The prothallia were regularly dioecious, and at this time no 
monoecious prothallia were observed. That these antheridia and arche- 
gonia were functional is shown by the production of vigorous young sporo- 
phytes. One of these sporophytes lived five months in KNop’s solution, 
and developed five fronds, one of which was 2.5°™ in length. Twelve 
weeks after the transference of the prothallia to the nutritive solutions, 
_many monoecious ones were observed in the cultures of KNop’s solution. 
These first developed the meristem with archegonia, afterward antheridia 
were formed from the marginal and ventral cells of the adventitious out- 
growths. 
CAMPBELL (/. c. 321) makes the statement that “‘as soon as an 
archegonium is fertilized, no new ones form, but it frequently happens that 
a very large number prove abortive before finally fertilization is effecte dd.” 
In all the cultures examined, both from the soil and the nutritive solutions, 
frequently prothallia have been observed producing new archegonia after 
fertilization had taken place. In the solution cultures young archegonia, 
antheridia, and sporophytes were present at the same time upon the same 
prothallia. 
A further attempt to produce monoeciousness was made, by transferring 
prothallia bearing archegonia from one nutritive solution to another. 
Results were obtained in the following cultures: (a) from KNopP’s solution 
to BEYERINCK’s solution, lacking potassium dihydrogen phosphate; 
- (6) from Sacus’s solution with 1 per cent. potassium phosphate, to Knor’s 
solution. In these cultures, three to four weeks after the transfer on 
