APPENDIX. 
IC7 
APOSPORY IN FERNS. 
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 December 1 8, 1884.) 
V\R. C. T. Druery has already drawn the attention of the 
Society, in two successive papers, to Athyrium Filix-foemina, 
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 without 
subjecting the matter to a detailed microscopical investigation. 
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 process. Without 
further recapitulation of Mr. Druery’s results, I may at once 
proceed briefly to describe the observations which 1 have made 
on the cultures now in progress at Kew. Many minute details 
will be deferred for the present, till the investigation is com- 
pleted ; 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 condition 
in which the specimens were when first I received them 
(November 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 develop- 
ment 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 the head, the result being that the 
arrested sporangium ultimately appears as a club-shaped body 
of larger size than the normal sporangium. The individual cells 
also are of larger size; they contain numerous chlorophyll 
granules, which, if present at all in normal sporangia, are 
relatively few in number. Further, the more rudimentary the 
head of the sporangium is, the more marked is the vegetative 
development of the remaining parts. 
