APOSPOEY IN FERNS. 
157 
On Apospory in Ferns (with special reference to Mr. Charles T. 
Druery’s Observations). By F. O. Bower, M.A., F.L.S. 
(Extract). 
[Read 18th December, 1884.] 
Mr. C. T. Drueey has already drawn the attention of the 
Society, in two successive papers, to Athyrium Filix-fcemina, 
var. Clarissima, ascribing to that plant a mode of transition 
from the sporophore generation (or Fern-plant), to the oophore 
(or prothallus), without the intervention of spores. He has 
pursued the subject with success, as far as it is possible with- 
out subjecting the matter to a detailed microscopical investiga- 
tion. We are indebted to this observer, not only for the 
communications already received from him, but also for his 
generosity in supplying to the Royal Gardens at Kew material 
fitted for the more detailed microscopical analysis of the pro- 
cess. Without further recapitulation of Mr. Druery’s results, 
I may at once proceed briefly to describe the observations 
which I have made on the cultures now in progress at Kew. 
Many minute details will be deferred for the present, till the 
investigation is completed ; the chief results are, however, of 
such importance as to justify a preliminary notice of them. 
The sori in Athyrium Filix-foemina, var. Clarissima, appear 
in the normal position with a normal indusium. In the con- 
dition in which the specimens were when first I received 
them (Kov. 29), the large majority of the sporangia presented 
an abnormal appearance. Some few appeared of nearly normal 
structure, with an annulus, but were arrested at a point of 
development before the formation of the spores; others, and 
indeed the majority of them, showed more or less distinctly 
the central archespore, together with the cells which would 
normally form the wall of the sporangium; but there the 
normal development seemed to have been suddenly arrested 
— the archespore had not in these cases divided further to 
form either the tapetum or the mother-cells of the spores. The 
arrest of development of the archespore is, however, compensated 
in these cases by the more active vegetative development of 
the stalk of the sporangium and of the superficial cells of 
