1920] 



CHILD &• BELLAMY— BRYOPHYLLUM 



261 



and show shoots as well as roots. Fig. 4 shows clearly the differ- 

 ence between A and the other leaves, although it does not show 

 all the development in B, C, and D. The more advanced develop- 

 ment of the four buds in D suggests that the eight days in water 

 preceding the temperature experiment may have had some slight 

 effect in the way of isolation, although it did not lead to visible 

 development. 



Series 45, April 4, 19 19. — Temperature 2 . 5-3 C. on one leaf (A) 

 of sixth pair below tip; B, opposite leaf, C, one leaf of seventh pair, 

 Z), one leaf of eighth pair, 

 and E, one leaf of fifth pair 

 also in water. After seven 

 days the cooled zone was . 

 gradually brought to room 

 temperature and the coil 

 removed. Fig. 5 shows the 

 plant seventeen days after 

 beginning of the experi- 

 ment. In A fourteen buds 

 out of fifteen submerged 

 developed and formed vig- 

 orous shoots; in B seven 

 out of fifteen submerged 



developed to some extent, but produced only roots; in C eleven 

 out of fifteen submerged showed some development, but only two 

 produced shoots; D showed no growth; in E all buds submerged 

 (thirteen) developed, but only six produced shoots. The growth 

 on leaf C is not well shown in the figure. The slight develop- 

 ment in the leaf B of this experiment is unusual. In most cases 

 the mate of the experimental leaf shows almost or quite as much 

 growth as the experimental leaf itself. 



Series 43, March 27, 1909. — Temperature of 2 . 5-3 C. on petiole 

 of one leaf (A) of eighth pair; only the terminal leaflet in water; 

 B. leaf opposite A, C, one leaf of eleventh pair, D. E, terminal leaf- 

 lets of leaves of ninth pair, F, one leaf of seventh pair, G, one leaf 

 of fifth pair, all in water. After six days the cooled zone was 

 gradually brought to room temperature and the coil removed. 



Fig. 4 



