On CROSS- and SELE-FERTILIZATION 
among PLANTS. 
byes J. HaAnvny Gipson, MOA? BL:S:, FR.S.E:, 
LECTURER ON BOTANY IN UNIVERSITY COLLEGE, LIVERPOOL. 
[Read 9th May, 1890.] 
In discussing the question of cross- and self-fertilization, 
investigators have confined their attention almost, if not 
entirely to the Phanerogamia. Muller makes a brief 
reference to the Thallophyta, Bryophyta, and Vascular 
Cryptogams,* but more by way of pointing out the hiatus 
in our knowledge with regard to the phenomena of fer- 
tilization among the Cryptogamia than of attempting to 
fill it. 
The Darwinian aphorism ‘“ Nature abhors perpetual 
self-fertilization”’ has not been accepted by all botanists 
as a complete statement of the case, or as the expression 
of a law of universal or even of very wide application. 
Muller himself, though a strong supporter of the efficacy 
of cross-fertilization, follows Axell in admitting and indeed 
urging the importance of self-fertilization in certain groups 
of plants, e.g. those with cleistogamous flowers. Meehan + 
again considers that self-fertilized plants have existed 
quite as long on the earth’s surface as cross-fertilized 
forms, and that the injuriousness of self-fertilization 
which Darwin emphasised does not express a fact, since 
self-fertilized are in every way as healthy as cross-fertilized 
plants. Henslow goes even farther. In the conclusion 
* Die Befruchtung der Blumen. Eng. Ed. p. 14. 
+ Proc. Amer. Assoc. Ady. Se. vol. xxiv., p. 243, 
