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APPENDIX. 
immediately began, sa that in a week or two each sorus had 
produced a crowd of full-sized prothalli. Reporting progress to 
Dr. F. W. Stansfield, who had also received material, he wrote 
that in his case apical apospory was also appearing, i.e., 
prothalli were being developed from the apices independently of 
the sori. Examining my material, 1 found several apparent 
cases of this, which, however, on closer investigation 1 found 
to be produced from small aborted sori situated so near the 
terminal point that the resulting prothalli seemed to spring 
therefrom. 1 therefore asked Dr. Stansfield to re-examine his 
material, with the result that in the majority of cases he 
found the appearance had been deceptive, but in some the 
apices themselves were certainly dilating. A little later 1 found 
an unmistakable instance of an apical prothallus, as can be 
seen by the culture 1 exhibit. Otherwise this case is identical 
with that of Athyrium Filix-foemina, var. Clarissima, Jones, 
except that the growths are much more redundant. I have 
named the Fern therefore Athyrium Filix-foemina, var. Clarissima, 
Bolton. 
It will be observed that in this case, as in all previous ones, 
the abnormality occurs on wild finds, and has not been induced by 
culture, and considering the ease with which the prothalli are 
produced when the pinnae are brought into contact with the soil, 
and the immense advantage which they must derive from being 
firmly attached to the frond from the beginning instead of, as in 
Ihe detached spore, being at the mercy of a thousand and one 
disturbing factors, it is curious that the specimens found are 
solitary crowns instead of clumps. This advantage, however, in 
the struggle for existence is far more than counterbalanced by 
the absence of scattering spores, which limits the variety strictly 
to its birthplace. 
Finally, I exhibit young plants raised from the aposporous 
prothalli of Lastrea pseudo-mas, var. cristata, which I brought 
to the notice of this Society in November, 1892. These are 
interesting as exemplifying exactly intermediate stages between 
the oophore and sporophore, the primary fronds in some cases 
consisting of erect prothalli borne on stalks, while in the case 
of the parent the primary frond had been eaten off when the 
plant came under notice owing to a prothallus forming at the 
tip of the second frond, and others subsequently on its edges and 
surface. This exhibit was therefore necessary to complete the 
case by supplying the missing step, which it does, I think, very 
satisfactorily. 
