

On the Cytology of Apogamy and Apospory. 463 
against the osmotic attraction of the dissolved salts; while the maintenance 
of equilibrium along the vessels of the balanced osmotic column, with its semi- 
permeable partitions, demands that an equal amount of water must rise 
spontaneously to take the place of what is thus removed. 
The subject might, perhaps, be further elucidated by observation of the 
manner in which the flow is first established at the beginning of the season, 
or possibly by experiments on the rate at which water would be absorbed by 
a wounded stem high above the ground. 
On the Cytology of Apogamy and Apospory.—ll. Prelimanary | 
Note on Apospory. 
By Miss L. Dicy. 
(Communicated by Professor J. B. Farmer, F.R.S. Received April 15,—Read 
| May 11, 1905.) 
Apospory is the direct vegetative process which leads from the sporophyte 
to the gametophyte without the intervention of spores. This phenomenon 
has for a long time been known to occur in mosses* and ferns, and several 
writers have described its morphological characters, but its cytological history 
has hitherto remained unrecorded. In a previous note} the cellular features 
of apogamy were briefly described, and it is here proposed to treat the problem 
of apospory in a similar manner. The following remarks are limited to the 
study of apospory in Nephrodiwm pseudo-mas Rich. var. cristata apospora, 
Druery,§ but it is of interest to note that within the limits of a (probably) 
single, but highly variable species, almost all grades of apospory and 
* N. Pringsheim, “ Vegetative Sprossung der Moosfriichte,” ‘Monatsb. Akad. Wiss., 
Berlin,’ July 10, 1876, pp. 425 to 429. 
K. Stahl, “ Ueber kiinstlich hervorgerufene Protonema-bildung an dem Sporogonium 
der Laubmoose,” ‘ Bot. Zeitg.,’ vol. 34, 1876, pp. 689 to 695. 
N. Pringsheim, “Ueber Sprossung der Moosfriichte und den Generationwechsel der 
Thallophyten,” ‘Jahrb. fiir wiss. Bot.,’ vol. 11, 1878, pp. 1 to 46. 
t+ C. T. Druery, “Observations on a Singular Mode of Development in the Lady Fern 
(Athyrium Filix-femina),” ‘Jour. Linn. Soc. Bot., vol. 21, 1884, pp. 354 to 358 and 
pp. 358 to 360. 
F. O. Bower, “ Apospory and Allied Phenomena,” ‘Trans. Linn. Soc. Bot.,’ 2nd series, 
vol. 2, Part 14, July, 1887, pp. 301 to 326. 
{ J. B. Farmer, J. E. S. Moore, and L. Digby, “ Preliminary Note on Apogamy,” 
‘Roy. Soc. Proc.,’ vol. 71, 1903, pp. 453 to 457. 
§ See “ Lastrea pseudo-mas var. cristata apospora,” C. T. Druery, ‘Book of British 
Ferns,’ p. 99. 
VOU, LXXvi.—B. DT 
