14 INDUCTION, DEVELOPMENT, AND HERITABILITY OF FASCIATIONS. 
individual needs, for seed from the fasciated wild O. dzennts of 1905, in which 
the tendency toward fasciation was so marked, when sown in the garden in 
1906 produced only one fasciation. The plants of this group flowered very 
early, however, and the time of sowing may have been as important a 
factor as the change of environment, or even more so. 
That fasciation can be produced by mechanical injury has been known 
for many years, and Sachs (6) and Goebel (16) both treat of the old exper- 
iment where, by cutting off the epicotyl of certain germinating seedlings, 
the side-branches forced out are flattened. Phaseolus multiflorus is most 
commonly used, while de Vries employed .4gvostemna githago (19). Nas- 
turtiums also respond readily, and as high as 60 per cent of fasciated 
individuals was obtained in one water-culture. The injury must occur 
just after germination, and this has led to the theory that the anomaly 
is caused by overplus of nutrition rushing to undeveloped centers of growth 
(16). The effects in the seedling are not lasting, for the flattened branches 
soon revert to the normal shape. It is possible that the remoteness of the 
stimulus from the meristems affected may have to do with this. In the 
cenotheras the injury is to the initial meristem itself, and is of a nature so 
delicate that no relatively coarse instrument can duplicate it artificially. 
Repeated attempts were made to induce fasciation in the primroses with 
incisions by fine sterilized needles, but the needles either destroyed the 
apex altogether, in which case the side-branch did not fasciate, or failed to 
reach it at all. Any incisions that could be made were so destructive com- 
pared with those of the sort represented in plate v, fig. 13, that the attempt 
was finally abandoned altogether. It is interesting to note, in support of 
the theory of the influence of nutrition, that the effects in the cenotheras 
come during the rosette stage and just before flowering, the times when the 
elaborated food supply is most abundantly centered at the growing apex. 
The discussion of the nature of fasciation has centered about the mor- 
phology of the enlarged axis, whether it is the enlargement of a single 
growing point, as exemplified by MouquinsTandon (2), or whether it is the 
adnation of several axes, as explained by Masters (3). After a careful 
histological examination of fasciated growing tips of certain Phanerogams 
and Cryptogams, Nestler (7) found no evidence in favor of congenital adhe- 
sion. The growing line gave no sign of complexes of growing points, but 
represented an enlarged area of meristematic cells. In the cenotheras there 
has never been any evidence in favor of the concrescence theory. In one 
single bifurcation for a short distance the epidermis closed around two 
separate axes, but this was accidental grafting of two separate tips. The 
phenomena of fasciation are phenomena of multiplication, of increase in 
“numbers of stems and leaves, and of the number of cells which enter into 
their composition. Once the physiological balance of the growing cells is 
changed and the chemical equilibrium altered by the peculiar stimulus of 
the mechanical contact, the tendency to multiply develops, and frequently 
