Oliver . — The Ovules of the older Gymnosperms. 461 
(Fig. 9). The seed appears to lack a sarcotesta, and so far 
agrees with such members of the Radiospermeae as had 
distinct nucellar bundles. But the chambered apex of the 
seed with its vascular prolongations constitutes an organ 
unique amongst the palaeozoic seeds. The peculiar form of 
the pollen-chamber is correlated with the distribution of the 
archegonia, which seem to have occupied a ring immediately 
beneath the bell-shaped crevice (as suggested in Fig. 9). 
Fig. 20. — Transverse section ot Lagenostoma cut near the apex at v in 
Fig. 9 (PI. XXIV). The section traverses the pollen-chamber/^., enclosed 
in its wall pew . ; cc. is the central cone of nucellar tissue ; t. testa ; c ., the 
fluted ‘canopy’; v., vascular strands running in the chambers of the 
‘ canopy’; g., chink between canopy and pollen-chamber wall. x 30 
(From the ‘ New Phytologist.’) 
Compared with the ordinary palaeozoic type of seed, 
Lagenostoma seems peculiar in the lack of tracheal supply 
beneath its pollen-chamber. Assuming that this deficiency is 
real and not due to imperfect preservation, there are at least 
two possibilities open in respect of the course of events in 
the pollen-chamber. The pollen-grains themselves, though 
