CURRENT LITERATURE 397 
.and give rise to particular races.” Considering all morpholog- 
ial peculiarities and physiological qualities as the results of heterogenesis, 
te must acknowledge that they do not differ in general from other types or 
existing from time immemorial, and which latter, based on the Dar- 
onan we ascribe with confidence as having developed by means of 
proportion of cultivated plants have come about, there comes the question : 
. Sthe event of the development of new forms by way of heterogenesis so sel- 
tom and exceptional? Does it not occur oftener than we think, and does it 
wtplay a certain rdle in the evolution of forms in the plant kingdom? 
- He takes up variability in garden plants under the most prominent forms, 
the many observations that have accumulated. Some of his 
sain topics are variations of growth, variations of stem, of crowns, form of 
: color of leaves, color of flowers, in structure of flowers, variations in 
and in fruits. On the basis of this study the peculiarities ¢ of 
characteristics are to be found in the more or less prominent 
; ily distinguished from the combinations of unimportant varia- 
hake up an individual in a group of its kind ; that is, 
ety or cena ic will be no- character 
in ‘the 
tions that they are constant, not only by vegetative — 
men propagated from seed, — Be fee in ae first 
aberrant forms may appea oe 
oy variability, hee their real cau ma be 
