Conopholis americana. 9 
It will be noticed that from all of these tubercles spring 
flower stalks in various stages of development. The larger 
tubercles, such as are figured in Plate I, are almost completely 
covered with such stalks. Curiously enough, however, there 
are few transition stages between the adult stalks and the very 
numerous young buds. The material was gathered near the 
close of the flowering period. Therefore, it may be that these 
buds remain dormant until the next year. It seems quite as 
probable however, that, like other parasites, they are capable 
of very rapid growth, and that transition stages are rarely 
found because the transformation takes place rapidly. 
The buds are protected by the scale leaves, which, in the 
young state, are rather fleshy than membranous. The tubercle 
itself is covered with a thick, coarse, porous, dark-brown 
“bark,” which scarcely holds together the innumerable gran- 
ules of sclerenchyma which make up the great mass of the 
excrescence. Plates II and III, which are photographs of a 
tubercle and the host oak root cut through the middle, show 
quite clearly the enormous quantity of sclerenchyma in sucha 
growth. Plate V, Fig. 5, is a drawing of a cross section 
through one of these patches. It will be noticed that it 
resembles markedly sclerenchyma groups, which are normally 
developed in the cortex of the oak, and are, indeed, character- 
istic of it. 
These photographs do not show what was particularly 
striking in the material itself, namely, that wherever a flower 
stalk had been, there were left behind large masses of scleren- 
chyma embedded in dead cellular tissue. 
Plates II and III alike show three large nodules, the centres 
of which are undoubtedly oak, much more compact and with 
fewer groups of sclerenchyma than the others. The lower 
nodule of Plate II indicates, perhaps, how the oak wood grad- 
ually became isolated from the surrounding wood, thus form- 
ing apparently comparatively unattached centres. The middle 
one of these three large nodules dropped from the rest, plainly 
