Hitcucock: TOLYPELLA LONGICOMA IN CAYUGA LAKE 175 
The heads are made up of verticils of fruiting leaves at the 
ends of very short stem branches within the upper large stem 
verticils. Braun writes: “fertile verticils bunched; bunches 
complicated by axilliary shoots.”” Doubtless the “‘axilliary 
shoots’’ are the stem branches mentioned and this reference to 
the structure of the heads tends to confirm the species relation. 
The stem branches may be 2-5 mm. in length or less, with 
whorls of six or seven fertile leaves having very short kasal 
segments. 
Antheridia are usually sessile but occasionally are borne on 
pedicels equaling their own diameter. Sporophydia are some- 
times very short stiped —my impression is that this applies only 
to those which develop in the fundus of a verticil. 
As the spores ripen for fertilization the neck-cells of the 
sporostegium become greatly enlarged (see Fics. 6, 7). Such 
conspicuous enlargement is not common in the family but is 
notable in T. glomerata and in Nitella opaca, which also is found 
about Ithaca. I have not seen the processes of fertilization but I 
have seen the opening of antheridia and the swimming sperms. 
Now, with plants of this family generally, mature fruits may be 
found in the lower verticils, while the earlier stages may be seen 
above. Therefore it is remarkable, if the number of specimens 
I have collected during two seasons is considered, that I have 
not found on a growing plant a single mature fruit, such as is re- 
quired to determine the markings and color of the mature spore. 
Possibly my collection at the time when sporophydia and 
antheridia were numerous happened to be made a few days 
before any fruit had matured on any of the plants. In less 
than ten days thereafter the plants had utterly disappeared. 
There is here a gap in my record much to be deplored. 
In other species the cells of the sporostegium kecome active 
after fertilization in forming a lignified, colored membrane 
around the spore, which may have various thickenings or 
spiral striae. I have not been able to discover any indication 
of the development of such a spore membrane in any growing 
plant collected. By careful manipulation the sporostegium 
envelope may be separated from the young spore which is then 
seen to have a thin, hyaline coat well filled with starch. One 
such spore is shown in Fic. 7. Many such dissections have 
failed to reveal any indication of further membrane development. 
