MISCELLANEOUS: EXPERIMENTAL TERATOSIS 615 



shoots relate to: (1) dwarfing or disappearance of parts, (2) dis- 

 tortion or enlargement of parts, (3) duplication or fusion 

 of parts. For example, we may have petiole absent, petiole 

 very short, petiole twice the length of the blade, petioles fused; 

 blades widened and cleft at apex (variously 2-lobed), sinus 'at 

 base closed (Tropaeolum leaf), blades spatulate (petunia leaf), 

 blades destitute of serratures or serratures reduced to mere 

 undulations, blades deeply incised (grape leaf), blades with 

 basal lobes widened so as to be triangular in outline (ivy leaf), 

 blades abnormally short and broad, blades abnormally long and 

 narrow (olive leaf), tissue mostly wanting on one side, w r hole 

 blade abortive, basal obliquity absent, two blades partly fused, 

 i.e., petiole fusion continued into the blade. 



30. The shock is something which either causes the develop- 

 ment of totipotent cells, out of young peripheral unipotent or 

 pluripotent cells (the cambium of the plant is not involved) 

 or else causes great numbers of totipotent cells, already present 

 in the epidermis chiefly in its appendages (hairs and glands) 

 but dormant, to be shocked into division, after which, that is, 

 when the plant has acquired a new root-system and general 

 growth has recommenced, they continue to grow until they 

 appear above the surface as young plants bedded in the tissues 

 of the mother plant. 



31. That the plant requires only a moderate amount of 

 water for its well-being is well-known to gardeners. This is 

 indicated structurally both by its elaborate sub-epidermal 

 storage system (hypoderm) and by its paucity of transpiring 

 organs. On the green stems there are no stomata, so far as I 

 have been able to see, but only a few lenticels, and on the leaves 

 there are fewer stomata than one would expect from their abun- 







was folded and only % inch long when slit. Leaf wounded March 30 (Ii of 

 Table I). Photographed April 25. X 5. 



BI, B 2 . Effect of dwarfing on production of shoots from the edges of wounds. 

 Leaves from IV i and IV 2 (.Table I). Leaves wounded March 30 when quite small. 

 The large leaf developed 283 shoots of which 241 were in the vicinity of the wounds. 

 The small dwarfed leaf developed only 8 shoots, all from the edges of the wounds. 

 Photographed May 3, 1918. % natural size. 



C. Two leaves grown together along middle part of dorsum. Adventitious 

 shoot from a leaf-blade. X 5. 



