IN THE BRYOPHYTA 205 
‘An examination of the origin of this dorsiventrality, thus seen in an 
organ which is as a rule of radia} construction, has shown that it appears 
relatively late in the course of the individual development, and is thus 
secondary. The young embryo of Funaria is a radially constructed 
spindle, and the inequality only appears as the capsule approaches 
FIG. 103. 
3. Diagrammatic longitudinal section through the green capsule of Physcomitrinm 
pyrtforme. X14. 5. Median longitudinal section through the mature green capsule 
of Aunaria hygrometrica. “20, 8. Profile view of mature capsule of the dorsiventral 
capsule of Buxbaumia aphylla. g. Median Jon: gitudinal section of the same capsule ; 
Z=cylindrical air-space; at s the stomata. zo, 10, Transverse section of the same 
capsule, about the middle. xo. (After Hz nelonds 
maturity. In the Buxbaumieae the dorsiventrality is more marked: 
the sporogonium of Dzphyscium shows when young a. characteristically 
radial cell-net; but external examination of even young sporogonia shows 
that the dorsiventral form of the capsule as a whole can be recognised 
comparatively early: a condition which accords with its very pronounced 
lopsidedness when mature. An enquiry into the circumstances which 
