185 



beside it is a smaller one about 2 mm. in diameter, darker in color. 

 Some young sporophytes are also shown in this photograph. 



Upon dissection, the prothallia were seen to consist of a basal 

 parenchymatous tissue, from the lower surface of which rhizoids 

 developed. On the upper side of this tissue erect branches were pro- 

 duced, which above were variously lobed and fringed. This struc- 

 ture corresponds with that described by Miss Walker (1931) for 

 the "normal thalli." She has taken up in detail the development and 

 distribution of the archegonia and antheridia. 



Miss Walker has also described male gametophytes in this spe- 

 cies, growing under crowded Conditions in culture, while Schratz 

 ( 1928) found small male gametophytes, which early darkened and 

 died, growing in the field. In the material found in Connecticut 

 there were numerous small gametophytes, mostly brownish or black 

 in color, which had died, though presumably not as a result of over- 

 crowding. Whether or not these were strictly male was not estab- 

 lished, though they seem to correspond with those described as male 

 by Schratz. They did not bear sporophytes. They are visible as 

 small dark sports in figure 2. 



During the time that these plants were kept under observation 

 in the field, the sporophytes developed considerably. On June 18 

 young sporophytes were visible, and one month later they were large 

 and conspicuous, though some were still beginning growth at that 

 time. Figure 3, taken on July 8, shows young sporophytes growing 

 from the old gametophytes, some of which are visible. The gameto- 

 phytes gradually died ofif, but on July 19 many could still be found, 

 associated with the sporophytes or growing alone. 



It was not uncommon for one gametophyte to bear more than 

 one sporophyte. Miss Walker (1921) states that as many as eleven 

 young sporophytes may begin development on one gametophyte in 

 E. laevigatum, though not more than seven were found large enough 

 to be visible to the naked eye. According to Kashyap (1914), E. 

 dehile gametophytes not uncommonly bear eight or ten sporophytes, 

 and he figures one which he states had fifteen. In the material from 

 Connecticut it was not uncommon to find several sporophytes origi- 

 nating on the same gametophyte. Figure 4 shows such a gameto- 

 phyte, bearing two sporophytes, each of which is made up of a pri- 

 mary and a secondary shoot. 



