262 MR. F. W. STANSFIELD ON APOSPORY IN 
On the Production of Apospory by Environment in Athyrium 
Filix-femina, var. unco-glomefatum, an apparently barren 
Fern. By F. W. SrawsrIElD, M.B. (Communicated by 
C. T. Davznv, F.L.S.) 
[Read 2nd February, 1899.) 
Tire form of lady-fern which is the subject of the present paper 
is of such a remarkable character that it will be well to give 
its history ; and fortunately this can be done in very few words. 
Its pedigree commences with A. Filix-femina, var. acrocladon, an 
extremely ramose, or, as fern-fanciers would say, a ramosissimum 
form, which was found wild in Yorkshire in 1860 by Mr. C. 
Monkman. Until about 1877 acrocladon was supposed to be a 
barren fern, and was propagated only by division. In 1877 my 
brother and 1 noticed spores upon a plant of it, and these were 
"arefully collected and sown, From this sowing there resulted, 
in the following year, a fair crop of plants, of which about one- 
third were true acrocladon. The remainiug two-thirds were mostly 
weeds —7. e. irregular forms, worthless from the decorative point 
of view. There were two plauta, however, which were considered 
to be advances upon aerocladon in the matter of extreme develop- 
menut. One of them was A. Filie-femina, var. unco-glomeratum, 
so named by the late Colonel A. M. Jones because, along with 
the glomerate character of acrocladon, it possessed the peculiar 
subdivision of parts which is characteristic of the variety wacum 
of Barnes. Whether it was the result of a cross between 
wncum and aerocladon it is impossible to say, but it is not 
improbable that this was the case, inasmuch as the parent acro- 
cladon was growing in a house with a large number of other 
ferns; and under these circumstances (or, indeed, under almost 
any eireumstances) it is impossible to exclude stray spores of 
other ferus which may settle upon the spore-bearer. 
A. Filiv-fomina, var. unco-glomeratum proved to be a very 
beautiful form, but exceedingly refraetory in the hands of the 
propagator. During nearly twenty years only some three or four 
divisions were obtained, and two years ago there is reason to believe 
that only two or three plants were in existence. The plant had 
shown in my hands no tendency to produce spores or bulbils, nor 
did there seem the slightest reason to suppose that it was capable 
