Intumescences in Hibiscus vitifolius, Linn. 17 



given the other necessary conditions, the formation of outgrowths is 

 promoted by heat. 



Large outgrowths may be artifically induced with certainty in about 

 two days on a single healthy branch (still attached to the plant), by 

 isolating it in a damp atmosphere, and exposing it to a strong light at 

 a high temperature. 



The following is a brief summary of the principal experiments and 

 conclusions : — 



Effects of Moisture. 



Number 

 of experi- 

 ment. 



1 



la 



lb 



2a 



2b 



3a 



3b 



3c 

 4 



Conditions of 

 experiment. 



Shoot in open air ; root in 

 moderately damp soil 



Shoot in air of greenhouse ; 

 root in wet, un drained 

 soil 



Shoot in open air ; root in 

 wet, undrained soil 



Shoot in air of greenhouse ; 

 root in damp, undrained 

 soil 



Shoot in open air ; root in 



damp, drained soil 

 Shoot in air of greenhouse ; 



root in damp, drained 



soil 



Shoot in damp air ; root in 

 damp, drained soil 



it ii ii 



Shoot in damp air : root in 



dry soil 

 Shoot in dry air ; root in 



dry soil 

 Shoot in very dry air ; 



root in dry soil 

 One shoot (attached to 

 the plant) isolated in 

 damp air 



One shoot (attached to 

 plant) isolated in water 



Result. 



No outgrowths 



formed 

 Outgrowths 



formed 



No outgrowth! 

 formed 



Outgrowths 

 formed 



No outgrowths 



formed 

 Outgrowths 



formed 



No outgrowths 

 formed 



Many out- 

 growths, on 

 the isolated 

 shoot only 



55 55 



A few out- 

 growths, on 

 the isolated 

 branch only 



No outgrowths 

 formed 



Remarks. 



Growth rapid and plant 

 very healthy. 



The leaTes soon drop- 

 ped off, and the plant 

 ultimately died, after 

 experiment was stop- 

 ped. 



Leaves dropped off, but 

 the plant recovered 

 when experiment was 

 stopped. 



Leaves became yellow 

 and curled under. 



Growth retarded 



55 53 



In bright sunlight and 

 hot weather. 



>» » ?» 



In cool, almost sunless | 

 weather. 



VOL. LXVIII. 



