8 9 
Teratological Seedlings . //. 
bundles supplying the lobes separated by the slight apical notch approached 
one another gradually and fused together in the lower portion of the lamina, 
whilst the vascular bundle so produced, and the bundle which supplied the 
third lobe of the cotyledon, entered the hypocotyl independently and pro- 
ceeded to rotate so that a triarch structure obtained (Fig. 7, d). This persisted 
throughout the hypocotyl and the major portion of the root, but in the 
•egion of the root tip two of the xylem plates approached one another and 
mally fused, this being accompanied by the disappearance of the interven- 
ing phloem group (Fig. 7, e and f). 
Seedling E. The last seedling of this type offered no points of out- 
standing interest. Both cotyledons showed slight apical fission, but whilst 
Fig. 8. a-f. Hemitetracotyl C. The bundles supplying the cotyledon lobes are lettered A-D. 
Diagrams b, c, d , show stages in fusion of bundles B and D. Diagrams e and f show fusion of 
A and C. Note that the fusing bundles supply lobes of distinct cotyledons, not the lobes of one 
cotyledon. 
in one case the two collateral bundles fused at the base of the petiole, the 
bundles of the other cotyledon remained distinct throughout, and a fairly 
prolonged triarch stage ensued, this being followed later by reduction to 
diarchy through the dying away of one of the poles connected with the 
bifurcated cotyledon. 
Tetracotyls. Only four examples of this type of polycotyly have been 
examined, and as these were all of type a or type j3 or showed combinations 
of the types they only demand a brief reference. 
In the simplest case the cotyledons were grouped in obvious pairs, 
union occurring between the corresponding vascular bundles at the apex of 
the hypocotyl, so that a normal diarch stele resulted. 
In a second seedling the vascular bundles of two of the cotyledons, on 
