EXPERIMENTS ON THE ROOTS OF PLANTS. 513 



nation found it was a domed nest of the willow wren (Sylvia trochilus). 

 Concerned at my precipitation, I put it down again as near the same 

 place as I could suppose, but with very little hope that the architect 

 would ever claim it again after such an attack. 



I was agreeably surprised to find, next day, that the little occupier 

 was still proceeding with its work. The feathers inside were increased, 

 as I could perceive by the alteration in colour. Whether this little 

 bird was attracted by the beauty or softness of the guinea fowls' fea- 

 thers (as there were a number kept about the house), I know not, but 

 they composed the principal part of the tapestry. 



In a few days, two eggs were laid, and I thought my little protege 

 safe from harm, when a flock of ducks, that had strayed from the 

 poultry-yard, with their usual curiosity, went straight to the nest, 

 (which was very conspicuous, as the grass had not grown high enough 

 to conceal it,) and with their bills spread it quite open, displaced the 

 eggs, and made the nest a complete ruin. I now despaired ; but im- 

 mediately on driving the authors of the mischief away, I tried to restore 

 the nest to something like the same form, and placed the eggs inside. 

 That day I was astonished to find an addition of another egg ; and in 

 about a week four more. The bird sate, and ultimately brought out 

 seven young ones ; but I cannot help supposing it a singular instance 

 of attachment and confidence, after being twice so rudely disturbed. 



ROSE. 



Blackburn, V]th April. 



EXPERIMENTS ON THE EXCREMENTITIOUS REJECTIONS 

 OF THE ROOTS OF PLANTS, WITH REFERENCE TO THE 

 ROTATION OF CROPS. 



BY M. MACAIRE, OF GENEVA. 



[The highly important paper, of which the following is a translation, has 

 been published in the fifth vol. of Mem. de la Soc. de Phys. et d'Hist. 

 Naturelle de Geneve. EDITOR.] 



FOR a considerable time, M. De Candolle has been led to form a 

 particular theory respecting the rotation of crops , founded on the 

 hypothesis, that the roots were the seat of secretions of an especial 

 nature. Some facts, already given in the Flore Franqaise by this 

 learned naturalist, seem to have furnished him with the first oppor- 

 tunity of turning his thoughts to this important subject ; he thus 



