Chap. I. 



OXALIS. 



25 



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, 

 '17 of an inch in length, and the hypocotyl was loft free. On 



Fig. U. 



,6°40'(».mJS^ 



Fig. 15. 



fta' ' 



fiS' 



7°22'f.». 



^•pW 



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 3} inches from the vertical 

 glass. Figure here given one-half of 

 original scale. 





Oxalis Valdiviana : 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 

 above. 



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

 grlasa j 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 

 'Jne following morning (June 19th) the apes of a cotyledon was 



