CHAP. I. 



OXALIS. 



ledons rise perpendicularly upwards at night so as to come into 

 close contact, instead of sinking vertically downwards, as in the 

 case of 0. rosea. A glass filament was fixed to a cotyledon, 

 C 17 of an inch in length, and the hypocotyl was left free. On 



Fig. 14. 



812'am. 



' Fig. 15. 



S4S' 



Oxalis rosea : conjoint circumnutation of 

 the cotyledons and hypocotyl, traced 

 from 8.12 A.M. on June 18th to 7.30 

 A.M. 19th. The apex of the cotyledon 

 stood only 3f inches from the vertical 

 glass. Figure here given one-half of 

 original scale. 



Oxalis Valdiviana i conjoint 

 circumnutation of a cotyle- 

 don and the hypocotyl, traced 

 on vertical glass, during 24 

 hours. Figure here given 

 one-half of original scale; 

 seedling illuminated from 



the first day the seedling was placed too far from the vertical 

 glass ; s J that the tracing was enormously exaggerated and the 

 movement could not be traced when the cotyledon either rose or 

 sank much; but it was clearly seen that the cotyledons rose 

 thrice and fell twice between 8.15 A.M. and 4.15 P.M. Early on 

 jhe following morning (June 19th) the apex of a cotyltdon was 



