1922] SPESSARD—LYCOPODIUM 405 
unavoidable, however, and this is especially true when prothallia 
of several kinds and of young age are found in the same lump of 
soil. The writer discovered such a mistake after a four months’ 
study of a single slide. Certain features relative to the fungus were 
found on it that did not occur in any of the other specimens to 
which it purported to belong. In fact, it was this discrepancy that 
led to the discovery of the mistaken identity of the prothallia under 
discussion. The habit of growth of the endophytic fungus will be 
discussed later. ; 
Fig. 70 shows a specimen of ZL. obscurum which looks like 
L. complanatum. The color and endophytic fungus both place it 
with the species assigned. Furthermore, the remarkable habit of 
growth of the antheridia was found present here, although the 
drawing does not show it. The enlarged antheridial mass shown 
in fig. 8: was taken from a specimen of a large L. complanatum 
prothallium. Both were rotted away at the lower end. Now 
_ no published figure of the last named species of prothallium shows 
that antheridia grow in such enormous masses. These facts can 
mean only one of two things, namely, that the fact of antheridial 
mass growth has not been observed, or that the form of L. obscurum 
prothallium is really intermediate between the L. complanatum and 
L. annotinum types. In view of the fact that other observers of 
L. complanatum prothallia were unlikely to overlook so conspicuous 
a feature, I am inclined to the view that the prothallia of L. obscurum 
occasionally take the intermediate position between the two well 
known types. After careful examination of the specimens found 
there is small likelihood of mistaken identity. If this be true, what 
I have called a prothallium of L. obscurum in my first paper (4) 
may need no modification. Moreover, the prothallia of L, Selago, 
L. lucidulum, and the peculiar specimen of L. obscurum all show a 
lateral groove more or less extensive, and are dorsiventral. 
SEX ORGANS 
The antheridia grow in enormous masses of white beadlike 
knobs. These may half encircle the entire prothallium in the adult, 
or may cause the very young to resemble cornucopiae. Such 
structures have not been observed by the writer on any other pro- 
