A. B. Stout 416 | 
the 7, were continued into the [,. Series 10-8-37 and 10-8-140 
especially were of vigorous growth. Fifty of the 56 plants of series 
10-8-37 were 6 or more feet tall and a few were 7 feet tall. The 
majority of the plants of 10-8-140 were from 54 to 6} feet tall. (See 
Plate IV at right with field label 26.) In these series were the largest, 
tallest and most vigorous plants that have thus far been grown in my 
cultures. The plants of series /0-8-173 were of somewhat smaller 
stature. 
The three series of the J, of the family 12-1/— were remarkably 
uniform in habit of growth as is well shown in Plate IV. The height 
scarcely varied more than 6 inches, Some plants in each series began 
blooming in June and were about 10-15 days earlier in blooming than 
_ plants of the family 10-8- 
Line breeding with self-fertilization for two generations has thus led 
to the isolation of families or lines differing in general vegetative vigour. 
One line continued to the J, exhibited a decided degeneracy which 
became more marked in the J, than in the J,. There may be some 
question as to whether this was due to some heritable factor of con- 
stitutional organization such for example as extreme conditions of 
fasciation, or whether a relation in sexual reproduction is operating 
as an immediate cause, as it appears to be in many degenerate hybrids 
and in the quite similar degeneratory offspring of certain illegitimate 
and weakly compatible matings reported in Lythrum Salicaria (Darwin 
1869, 1877). 
Two main lines maintained in both the J, and the J, a high degree 
of vegetative vigour and potential sex vigour, and one of these has 
seemed to-gain in vegetative vigour over that of the parent stock. The 
uniformity of these differences here suggests that constitutional and 
heritable “factors” for size are present, and are not perceptibly influenced 
by such variations in self-compatibility as may have occurred in the 
rather highly self-compatible parents. 
The readiness with which self-fertilized lines from parentage of high 
self-compatibility maintain a high degree of vegetative vigour is con- 
vincing evidence that self-fertilization is of itself not directly imjurious 
and productive of degeneracy. 
8-2 
