miscellaneous: experimental teratosis 593 



ones are visible), while the vast mass of the leaf remained free 

 or nearly free from such buds. On some leaves, as may be 

 seen from Table I, the lips of the wounds bore many times more 

 shoots than the rest of the blade, e.g., on the leaf from branch 

 I2, Ho of the surface (the wounded part) bore 183 shoots while 

 the remaining ^%o bore only 8 shoots; on the leaf from branch 

 nil, M9 of the surface bore 141 shoots while the remainder bore 

 only 5 shoots; on the leaf from branch Vo, ^43 of the surface 

 bore 58 shoots, the remainder only 3 shoots. The number of 

 shoots from wounds is strictly conditioned on the nutrition. 

 Generally each wounded leaf received enough food to enable a 

 portion at least of the adventive shoots to develop, but occasion- 

 ally not (see Fig. 448^2 and the footnote to Table I). 



16. This local response, however, did not explain the origin 

 of extra-axillary buds in the absence of visible wounds and I 

 was especially puzzled by the fact that often one or two inter- 

 nodes or leaves on a plant would bear hundreds of these adven- 

 titious buds (Figs. 426, 427) while all the others were free or 

 nearly free from them (Fig. 425, exclusive of .x.) 



17. Believing the response must be due to excessive loss of 

 water I next tried the drying of cuttings for a short time before 

 planting them. In this way, frequently, I obtained more or less 

 striking results at the top of the plant, i.e., in the parts which 

 were embryonic at the time of making the cuttings, especially 

 if the cuttings were allowed to dry for a day or two before plant- 

 ing, but this method did not give as uniform results as the follow- 

 ing, especially when the drying period was short. 



18. In the spring of 1918 I discovered that the striking re- 

 sponse referred to under 16 was due to root-injury sustained at 

 the time of repotting. The results of my preliminary observa- 

 tions were so convincing that I had no doubt as to the correct- 

 ness of my conclusions, i.e., that the very copious restricted or 

 regional response was due to root-injury acting on young tissues. 



B. No. 9, first series. Entire main axis (leaves removed). The two proli- 

 ferous internodes, at X, Y, were embryonic and stipule-wrapped on July 25. 

 For the opposite side of a part of X in more detail see Fig. 439>4.. Photographed 

 October 10, 1918. Reduced. 



C. Shoot arising from a hair on a petiole. The trichoma top is shoved over 

 to the left and its base is much thickened. X 10. 



38 



