INDUCTION, DEVELOPMENT, AND HERITABILITY OF FASCIATIONS. 13 
develop whose mouth-parts are sharper than those of their fellows, or whose 
habit it is to bore deep for the youngest and most tender food. In the 
same way there are swarms of imagos which have longer ovipositors, or 
which show a preference for the center of the apex rather than the axils of 
the embryonic flowers. If the character of the attacks of the insects varies 
with the character of the insect swarm, this should account for the wide- 
spread appearance of fasciation over one restricted locality, while in adja- 
cent areas, beyond but insignificant barriers, no fasciated plants are found. 
The ‘‘curious’’ habit of fasciated stems in that those of annuals are at 
first round and later flatten, while those of biennials originate large and flat 
and stay so, has been noted by de Vries (11). Inthe primroses under 
observation this seems to be accounted for by the state of development at 
the time of the sting of the insect. Inthe cultures of O. Jarvifora roscttes 
planted in the summer of 1905, and kept over, fasciated during the winter; 
those sown in February elongated quickly after being placed out and fas- 
ciated in the upper parts of the branches. Two plants of the February 
sowing, which grew more slowly than the others, were fasciated rosettes in 
September. In general, plants or branches which were in the rosette stage 
in July and August, or at the time when the insects were laying their eggs 
and the larve were hatching, fasciated as rosettes and produced flat stems 
the following season. Plants in the flowering state during the same period 
fasciated in the upper part of the stems. Plants elongating from the 
rosette stage in September fasciated comparatively low down on the stem as 
in plate m1, fig.6. Any plant, moreover, may fasciate in its rosette stage 
the first season, and in the upper part of its side branches the second 
season. To secure the most striking results in New York, seed should be 
planted in April or May and allowed to remain out of doors in the rosette 
stage through the summer. Plants from seed sown in February begin to 
elongate too early to show linear growth long before the flowering tips are 
ripe. So many of the wild plants are aborted in the main axis that one 
may assume that the tip is eaten off by larvee soon after the plant elongates 
from the rosette stage. Among the wild plants there were many larvze 
in the field in June in the young shoots. The side-branches are doubtless 
injured as they are forced out, for the callus in the grooves of some of the 
branches and in the lower parts of the cavity of the rings in others indicates 
early effects of injury in these secondary branches. 
The conditions of culture, as has been already stated, were favorable to 
the vigorous growth of the garden plants. Individuals were from 2 to 4 
feet apart and were well-fertilized and watered. The interesting experi- 
ments of de Vries and of Hus (22) at the Missouri Botanical Garden sug- 
gest that if some of the unfasciated plants had been subjected to different 
conditions they too might have fasciated. It is possible, also, that if the 
plants had been planted in April instead of in February the result might 
have been different. The environment must, however, be suited to the 
