312 PROF. Е. О. BOWER ON APOSPORY AND ALLIED PHENOMENA, 
It has been noticed by various observers and figured by Mr. Wollaston *, that the 
prothalli thus produced in a vegetative manner from the frond of this Fern ӨЗГЕ pro- 
liferation in a high degree, so that continuous series of prothalloid growths, derived 
successively from one another, may be seen still connected together. This has also been 
noted in various other Ferns, and is, indeed, not an uncommon condition T. Whether it 
has any special significance in the present case is not clear; but it is worthy of note that 
it is found to occur in a conspicuous degree in this variety, which shows such a remarkable 
tendency to other modes of proliferous growth. 
From the facts above stated, it is clear that in Polystichum angulare, var. pulcherrimum, 
not only may the oophore generation be derived by direct vegetative outgrowth from the 
sporophore, but further that this phenomenon makes its appearance in various ways, being 
by no means tied down to one strict type. It will be remembered that in the case of 
Athyrium F.-f. var. clarissima, the prothalli originate only from the sporangia; here, 
as regards their point of origin, no less than four types may be distinguished : these 
may be tabulated thus :— 
А ГА. From the extreme apex (figs. 18-21). 
io! у: | 
Р сы ig wi den TIN qr roS ds din outgrowths from the surface of the 
or near the tip of the pinnule or segment | 
of the pinnule. € pinnule (figs. 22-30). 
= (or ted ia (figs. 30-32 
The prothalloid outgrowths originate in . From arrested sporangia (figs. E 
А Я D. From the base of the sorus (figs. 34, 35). 
connection with the sorus. 
The two examples above described are cases of true “аровроғу,” and in both cases, 
so far as observation extended, the varieties showed a complete sporal arrest. A com- 
plete or partial arrest of spore-formation may also be recognized in other Ferns, as 
associated with substitutionary vegetative growth; but whereas in the former examples 
these substitutionary growths assumed the characters of the oophore (apospory), in 
those which will now be described they assume the characters of the sporophore, and 
may accordingly be placed under the head of “ sporophoric budding,” as above defined. 
But while recognizing the affinity of these growths to those buds which are commonly 
found on the fronds of Ferns (e. g. Asplenium bulbiferum), it must not be forgotten that 
in respect of the sporal arrest these cases are to be associated with those of true apospory. 
Athyrium Filix-femina, var. plumosum. 
Mr. Druery has already studied and described the formation of sporophoric buds in 
connection with the sorus in two subvarieties of the above variety, described under the 
names of elegans and divaricatum f, and there is little to be added to what he has 
written; still it will be well to put together the results of his observations, and of those 
* 
* Gard. Chron. 1885, p. 781. T See Goebel, Bot. Zeit. 1887, p. 681, &c. 
+ Gard. Chron. vol. xx. p. 783; Journ. Linn. Soc., Bot. xxi. p. 354, &c. 
