NOTES. 
ON APOGAMY AND THE DEVELOPMENT OP SPOR- 
ANGIA UPON PERN-PROTHALLI. By William H. Lang, 
M.B., B.Sc. 1 — The two most important deviations from the normal 
life-history of Ferns, apogamy and apospory, are of interest in them- 
selves, but acquire a more general importance from the possibility that 
their study may throw light on the nature of alternation of generations 
in archegoniate plants. They have been considered from this point 
of view by Pringsheim, and by those who, following him, regard the 
two generations as homologous with one another in the sense that 
the sporophyte arose by the gradual modification of individuals 
originally resembling the sexual plant. Celakovsky and Bower, on 
the other hand, maintain the view that the sporophyte, as an inter- 
polated stage in the life-history arising by elaboration of the zygote, 
is not the homologue of the gametophyte, and is only represented in 
a few Thallophytes. In the light of the theory of antithetic alternation 
no weight is attached to apogamy and apospory for phylogenetic 
purposes. 
In the paper of which this is an abstract, the results obtained by 
cultivating the prothalli of a number of species of Ferns under 
conditions slightly different from the natural ones are described, and 
their bearing on the problem of the nature of alternation considered. 
The behaviour of Scolopendrium vulgar e, Sm., and Nephr odium dila- 
tum , Desv., in which sporangia were borne upon the prothallus, has 
already been described in a preliminary statement 2 . It is therefore 
sufficient to express the results of prolonged cultivation of these and 
the remaining species in a tabular form. 
1 Abstract of a paper read before the Royal Society, March 3, 1898. 
a Roy. Soc. Proc., Vol. lx, p. 250. 
[Annals of Botany, Vol. XII. No. XLV I. June, 1898.] 
