Anatomy of Teratological Seedlings. III. 329 
fusion the effect of the ensuing compression on the laterals on that side 
becomes plainly evident (cf. Figs. 10 b, 11 b, 13 b, 14, 15, 16 b> 17 a , and 19). 
In one or two instances both persist in a much reduced condition, but do 
not form a root pole, and end blindly in the hypocotyl. More usually only 
one persists, and, though in one instance (Figs. 29-34) it remains prominent 
through the greater part of the hypocotyl and becomes mesarch, it ultimately 
dies out. Generally the persistent lateral is represented in the hypocotyl 
by a few metaxylem elements which have no effect on the trimerous 
symmetry which has resulted from syncotyly. In the lamina it is usually 
well-developed and often receives bundles from both cotyledons (Figs. 13 b , 
15, 19). The result of the further stages in syncotyly is to cause its com- 
plete suppression (Figs. 35-39), this being compensated to some extent by 
Figs. 35-39. Typical advanced syncotyl showing suppression of both laterals on the symphysis 
side and delay in the fusion of the lateral and marginal bundles. Note the two cotyledonary buds 
in Fig. 36. 
a slight elaboration of the lateral bundle-system of both cotyledons on the 
side remote from the symphysis (Figs. 35, 36). The other points common to 
the whole series are that where the seedling is sufficiently developed two 
cotyledonary buds are always present, and also that a short cotyledonary 
tube is practically a constant feature (Fig. 36). 
Reference has already been made to the precocious epicotyledonary 
vascular fusions incidental to the less extreme cases of syncotyly. This 
stage is followed by one showing a displacement of the vascular supply of 
the leaf of the first epicotyledonary node situated on the symphysis side, 
which, instead of retaining its normal position in the intercotyledonary plane, 
divides into two parts, one consisting of the midrib and one lateral bundle, 
and the other of a lateral bundle only. These fuse with the right and left 
laterals of the other leaf from the same node, so that the vascular supply of 
