ATHYRIUM FILIX-F@MINA, VAR. UNCO-GLOMERATUM. 267 
breaks out when once the tendency to branching has been 
exhausted and a free cellular tissue produced. 
(4) The variety of ways in which this occurs, viz.:— 
(1) Gemmation from the rhachis without production 
of prothalli. 
A (2) (a) Apogamic buds from the prothallus. 
pospory | (b) Normal sexual axes of growth from prothallus. 
(5) The ease with whieh apospory is induced in the primary 
fronds as compared with the extreme difficulty in the case of the 
adult fronds is characteristic of all aposporous ferns, so far as I 
know. 1 have at various times succeeded in raising plants by 
apospory from eight different ferns—four forms of Polystichum 
angulare, one of Lastrea paleacea, and three of Athyrium Filix- 
J'emina ; and in every case I have noticed that if the first fronds 
from the protballus were pinned down (and, indeed, frequently 
without this special treatment), the edges rapidly developed into 
prothalli. Assuming the truth of the recapitulation theorv 
(i.e. that ontogeny is an epitome of phylogeny), this would seem 
to suggest that apospory is an atavie trait in ferns—a character 
which may have been general or even universal in the infancy of 
the race. This idea is also borne out to some extent by the fact 
that apospory is favoured by a uniformly humid atmosphere, a 
condition which probably prevailed in early geologic (say Silurian 
and Devonian) times. 
(6) The prima facie unlikeliness of A. Filix-femina var. unco- 
glomeratum as a subject for apospory leads me to suspect that 
that phenomenon could be induced in many— possibly in most— 
ferns by taking suflieient trouble. This fern has apparently 
nothing in common with the other abnormal forms which have 
manifested apospory. All these, so far as I know, belong to the 
plumose or ultra-plumose sections of varieties. It is true that 
among them are two other crested ferns, viz., Cropper's Lastrea 
paleacea var. cristata pulcherrima and Scolopendrium var. crispum 
Drummondie; but both these are specially modified forms, whose 
appearance at once suggests to the experienced eye that they 
are likely subjects for apospory. It is evident that there is a 
wide field for further experiments in the cultural inducement of 
apospory. Some of these further experiments I hope to make 
and to record results in due time. 
LINN. JOURN.— BOTANY, VOL, XXXIV. U 
