MULTIPLICATION, 87 
variety he wishes to grow, but also because, if any other 
variety is grown in the neighborhood, its pollen is sure 
to impregnate his variety and produce a mongrel off- 
spring. Oross-fertilization then acts in antagonism to 
the hereditary tendency, and secures variation—and not 
only variation, but more vigorous and robust constitu- 
tion, and more numerous and more healthy descendants. 
Self-fertilization, or “‘in and in breeding,” occurs, no 
doubt, in some instances, especially in cereal grasses ; 
and there are indeed many cases where, for various rea- 
sons which need not be cited here, no other mode of fer- 
tilization is possible. Relative permanence of character 
is secured by this means, and if constitutional vigor and 
the health of the offspring be impaired by the long con- 
tinuance of the process, these ill-effects are provided 
against by the circumstance that a comparatively trifling 
change in the flower, or in the circumstances by which 
it is surrounded, will suffice to prevent self-fertilization 
and secure cross-fertilization. 
Fertilization of Cereals.—It has very generally been 
stated that the wind is the special agency by means of 
which the pollen is carried from flower to flower of these 
plants, and no doubt this is true to some extent and under 
certain circumstances. From the careful experiments and 
observations of Mr. A. S. Wilson, recorded in a paper read. 
before the Botanical Society of Edinburgh, Scotland, 
and printed in the ‘‘Gardener’s Chronicle,” March 14, 
1874, it appears that self-fertilization is the rule among 
cereals, though cross-fertilization does occasionally take 
place and has been effected artificially by various experi- 
menters. The flowers of wheat, barley, and oats open to 
a slight degree and allow the anthers to protrude, often 
quite suddenly ; but whether the flowers fully or but 
partially open, says Mr. W., they are fertilized before the 
anthers are visible outside. ‘‘'The Belgian farmers,” he 
