Anatomy of Teratological Seedlings. III. 331 
(ii) Reduction in the hypocotyl and root of the tetrarch to triarch 
symmetry. 
B. Young epicotyl. 
(i) Precocious fusion of the bundle-systems of the leaves of the second 
node on to that of the leaf of the basal node on the symphysis side. 
(ii) Reduction of the leaf of the basal node on the symphysis side and 
the division and lateral displacement of its vascular system. 
(iii) Complete suppression of this leaf, and possibly 
(iv) Reduction in the number of leaves at the third node from three to 
two with modification of the vascular relationships of one of the persistent 
members. 
Figs. 40-48. Figs. 40-43, young epicotyl in syncotyl showing reduction of one leaf of the 
basal pair and the modification of its bundle distribution. Figs. 44-48, young epicotyl of seedling 
with unequal cotyledons (Fig. 8) showing bundle distribution. Note the trimerous whorl at the 
second node and the precocious fusion of two of its members. * 
Comparing these results as regards the cotyledon with those obtained 
by Compton ( 3 ) in his study of syncotyls, it will be seen that up to a point 
the correspondence between the two is very close, but that the ultimate 
stages recorded by him for Helianthns annum syncotyleus , namely, partial 
union of the median bundles and, more doubtfully, partial suppression of 
one of the median bundles, are absent in the material of Impatiens Roylei. 
Compton apparently made no attempt to study the effect of advanced 
syncotyly on the young epicotyl. 
The second group of seedlings, seventeen in number, also form a very 
completely graded series. All the members of this group show what is 
apparently a single cotyledon with no macroscopic evidence of synco- 
tylous origin (Fig. 20). The first epicotyledonary node bears a single leaf 
Z 
