Notes , 
183 
PRELIMINARY NOTE ON THE FORMATION OF 
GEMMAE ON TRICHOMANES ALATUM. — The plant on 
which the observations now to be described were made belongs to the 
Edinburgh Botanic Garden. Through the kindness of Prof. Dickson, 
who had already noted a similar peculiarity in a species of Trichomanes 
in a private collection in Edinburgh, the plant was placed at my dis- 
posal for detailed observation and culture. As noted by Prof. Goebel 
in a recent work dealing with the germination of certain Ferns, and 
especially the Hymenophyllaceae the growth of the prothalli of 
this family is exceedingly slow, and, on this as well as on other 
grounds, I think it advisable not to delay the publication of facts 
already acquired till the close of the observations of cultures which 
are likely to extend over many months. 
The plant of Trichomanes alatum , on which these observations were 
made, is in a strong, healthy condition, and on the upper and larger 
leaves there are numerous sori, bearing apparently normal and mature 
spores. It is on the lower leaves that peculiarities of development are 
to be seen ; outgrowths of two kinds are formed at or near to the tips 
of the pinnae, and it is especially to be noted that they are actually 
vegetative outgrowths, as was shown to be the case in those aposporous 
Ferns which I have described elsewhere 2 . The outgrowths of the 
first type appear as ribbon-like prolongations of the laciniae of the 
frond, and several such may be found on a single leaf : they are only 
one layer in thickness, and may consist of two to four or more rows 
of thin-walled cells having the usual characteristics of a prothallus: 
they differ from the normal frond in the entire absence of those stiff 
hairs which are so numerous in this species. On the ends of these 
processes are borne numerous sterigmata [this term is adopted in the 
sense of Goebel, 1 . c. p. 82], many of which bear spindle-shaped 
gemmae similar in aspect and position to those described by Cramer 3 . 
Others may bear similar gemmae in various stages of development, while 
others again show merely a brownish point, where the mature gemma 
has broken away from its support. The results of cultivation of gemmae 
after removal from the sterigmata are as yet very incomplete, but I am 
in a position to state that germination does at least take place. 
The outgrowths of the second type may start from any single 
marginal cell of one of the lower leaves of the plant : this grows 
1 Ann. Jard. Bot. Buitenzorg, vol. vii. 2 Trans. Linn. Soc. vol. ii. Part 14. 
3 Denkschr, der Schweiz. Nat. Ges. xxviii. 
