HYMENOPHYLLACEAE 579 
later may be correlated with the close packing of the sporangia in the 
sorus. The view of the sporangium from the side on which dehiscence 
takes place shows that the annulus is not 
continued throughout as a distinct series 
of cells (Fig. 325, No. 96); but there is no 
definite group of cells of the stomium ; this 
feature is again comparable to that in GZ. 
circinata. The drawings of the central and 
peripheral faces (Fig. 325, Nos. 97, 98) will 
complete the knowledge of the external form 
of the sporangium in this species. The 
stalk is short and rather thick, and the 
insertion is by a rosette of cells, some six in 
number. 
For comparison with the sporangium of Fic. 324 dis, 
LHymenophyllum, that of Trichomanes vadicans Pieaeneiotion Wilsoni, Hk. Sorus 
is represented in Fig. 325, Nos. 99-102, as seen in longtudinal “seton "shoving. "the 
from four different points of view. No. rox  ¢alaty grow! and the first sporangia 
shows the sporangium presenting its central 
face ; the close analogy with No. 97 of Aym. dilatatum is obvious, though it 
is smaller in size, and with fewer cells in the annulus ; but fluctuations less in 
extent though similar in nature are found in 7+. radicans itself, the cells of 
Fic. 325. 
Nos. 95, 96, 97, 98=Sporangia of Hymenophyllum dilatatum. Swartz, seen respectively 
from cine Het (Nos. 95, 96), and from the central (No. 97), and peripheral (No. 98) 
faces. Nos. 90, 100, ror, roz=similar figures, to the same scale of 7richomanes 
radicans, Swartz. Nos. 99 and 100 show the lateral views. No. 101 shows the central, 
and No. 1o2 the peripheral faces. All x 50. 
the annulus varying between 20 and 25. There is also a greater simplicity in 
the region of the stomium,-which in 77chomanes is represented by two cells 
only. No. 102 represents the “ peripheral” face, the thin-walled region being 
surrounded by the annulus, which takes the form of a twisted hoop. This 
twisted form is clearly shown in No. 99, which demonstrates also the relation 
