254 FREAKS OF PLANT LIFE. 



ancc of this plant as seen by day, and as seen by 

 night. 



In Co7-onilla rosea the leaves have nine or ten pairs 

 of opposite leaflets, which during daytime project 

 horizontally. At night these leaflets rise so that the 

 opposite leaflets nearly touch each other, at the same 

 time they bend backwards and towards the stem, 

 sometimes to such an extent that their midribs are 

 parallel to the petiole. This position, both as 

 regards the uprising of the leaflets, and their direction 

 backwards on the petiole, is just the reverse of what 

 usually takes places in the order to which this plant 

 belongs. 



In making these experiments it was proved that in 

 order to exhibit fairly their nocturnal movements, 

 the soil of the plants must not be kept too dry. 

 Also that the temperature must not be kept too low ; 

 but this would naturally vary in different plants, 

 those which are natives of hot countries requiring a 

 higher temperature to exhibit their natural activity, 

 than those which arc denizens of a more temperate 

 clime. A plant out of doors, although in good 

 health, did not exhibit any nocturnal phenomena, 

 whilst a plant of the same species in a warm green- 

 house had its leaflets all drooping at night. In the 

 case of many plants it was also found indispensable 

 that the leaves should be well illuminated during the 

 day in order to their sleeping at niglit. One plant 



