42 Bower.—Studies in the Phytogeny of the Filicales. VIL 
has arisen by fusion ( connatus ) of hairs such as are seen in Pteris hetero - 
phylla. 
Naturally the latter species had to be examined and the truth of 
this observation tested. This was possible on material collected in 
Jamaica. It was found in sections cut vertically through the young 
sorus that the hairs are very numerous, but always distinct from one 
Fig. 29. cir-c. Vertical sections of the young sorus of Pteris longifolia. (x 150.) 
another, never webbed. The sporangia are relatively few. The position 
in which the first hairs (paraphyses) originate has no definite relation to 
the inner limit of the receptacle, where the inner indusium should be 
theoretically. They are sometimes found singly on the side next the 
upper or outer indusium (Fig. 30, a ); sometimes in a close group, cover¬ 
ing about half the width of the receptacle ( b ). In rather older states 
