Bower . — Studies in the Phytogeny of the Filicales. VL 1 3 
P. oethiopicum and angolense } and sections show even more decisively that 
the sporangia are not spread continuously over the whole surface ; on the 
other hand, the sporangia are usually orientated as in L. tricuspis , with the 
annulus lying in a plane transverse to the leaf. Comparing with species of 
Leptochilus^ as shown by Frau Schumann, 1 2 while there also the sporangia of 
different ages are intermixed, the first formed are seated upon the veins, 
thus indicating a soral origin. Hairs are present, but only occasionally, 
here and there, and are unbranched. 
The sporangium of L. tricuspis is of an ordinary Polypodiaceous type, 
with a stalk about twice as long, when fully extended, as the capsule itself. 
It is composed of three rows of cells, and each row consists, as a rule, of three 
Text-fig. 7. a, b, c. Sporangia of Leptochilus tricuspis. «, seen obliquely from the side of the 
stomium; b, from the opposite direction; ^sporangium cut in longitudinal section, x 125. 
cells. The segmentation of the young sporangium has been seen to be three- 
sided, according to the usual Polypodiaceous type, a character which it 
shares with Platycerium . The annulus of the mature sporangium consists 
of about thirteen indurated and eight non-indurated cells, including the 
stomium (Text-fig. 7, a , b, c ). It is not quite definitely interrupted at the 
stalk, for, as clearly shown in Text-fig. 7, c, which is drawn from a longi- 
tudinal section, the lowest cells on either side are actually in contact. The 
stomial cells are slightly thickened and rounded, so as to locate the rupture, 
and three thin-walled cells adjoin it on either side. These characters are 
what are commonly regarded as ‘ Polypodioid \ The sporangia correspond 
more closely to those of Platycerium 3 than of Dipteris or Cheiropleuria , for 
in the latter the stalk is four-rowed and the annulus is oblique and con- 
tinuous, though not fully indurated. 4 But in Platycerium the stalk is three- 
1 1 . c., p. 513, Figs. 13; 14. 2 Flora, 1915, p. 237, &c., Figs. 26-32. 
3 Studies, V, Text-fig. 18. 4 Studies, V, Text-fig. 17. 
