CROSS- AND SELF-FERTILIZATION AMONG PLANTS. 129. 
Again if we are to accept such observations as those of 
Henslow, Meehan and others on the high degree of pro- 
ductivity resulting from the “ self-fertilization”’ under 
certain conditions of flowers normally self-sterile, are we 
to conclude that the alterations brought about in the 
environment have so profoundly altered the physiological 
value of the reproductive cells, cells it 1s to be noted 
already mature and ready for ‘‘ cross-fertilization ”’ ? * 
Prof. D’Arcy Thompson in his preface to the trans- 
lation of Muller’s work says: “‘I have throughout used 
fertilization in preference to the ungainly word pollination, 
to imply application of pollen to the stigma without 
definite reference to the result of the act; that is to say, 
I have in ordinary cases translated Bestéubung and 
Befruchtung by the same word.” But the two processes 
are, aS every ons knows, essentially distinct. The applica- 
tion of pollen to the stigma is merely the approximation 
of the microspore to the megaspore and does not by any 
means involve fertilization. ‘‘ Pollination” is the term 
adopted by most leading botanists for the application of 
pollen to the stigma. Goebel,+ for instance, is careful to 
emphasise the importance of the distinction between the 
two processes. 
If then we accept the fact that Phanerogams are of 
necessity cross-fertilized from their heterosporous con- 
dition, the further problem, Is cross-pollination a univer- 
sal law or not? is left for solution. Into that question I 
do not intend to enter. 
The whole question of cross- versus self-fertilization in 
plants has, it seems to me, scarcely yet been touched; for 
as I have pointed out the very numerous investigations I 
*Henslow. Linn. Soc. Trans., 1. c., p. 325. 
+ Outlines of classification and Special Morphology of Plants, p. 306. 
