254f Experiments in Physiological Botany, 



pine-apples in a forward state, some ripe and others nearly 

 so, and the temperature was kept up from 65° to 80°. The 

 weather in the last eight days of January' was changeable; the 

 medium of heat was 43°, of cold 33it°; and the rain fallen in 

 the same time was only Jy\y of an inch. 



I examined both vines daily within the stove, and at the 

 roots. On the 2d of February the top buds of both were 

 turgid ; on the 3d, the top buds had shed off their envelope, 

 and were ready to break into leaf, and the other buds were 

 in successive progress. I then cut through the bark and 

 alburnum into the wood, but not to the medulla, the two 

 top joints bled freely, and the third was just moist, and at a 

 foot from the top they were quite dry ; the wounding and 

 examination of the roots was continued daily, and often twice 

 a day, and the sap descended in regular progress until it 

 reached the cavity between the fire-flue and front wall, when 

 a visible check appeared, which the vine nearest the fire-place 

 never got over. 



On the 20th of February, the protected and excited vine 

 began to bleed outside the wall, it had taken four days more 

 in passing the air-flue and wall, than in passing the same 

 space in the more temperate air of its upper parts. On the 

 21st, this vine bled freely at the surface of the soil; on the 

 23d, it began to make fibrous roots in the soil that enveloped 

 the whole ball, and put out fine, strong, new roots at the surface. 

 During the above interval of thirty days of the experiments, 

 and twenty-two days of vegetation, nearly all the buds on 

 this vine had vegetated in regular succession ; I never could 

 perceive the least check or stagnation in its leaves or shoots ; 

 it had two small bunches of grapes on it, which were just 

 coming into bloom, one of which was cut off. On the 28th 

 of February, a change of texture in the foliage began to ap- 

 pear ; the tender almost transparent green changed to a fixed, 

 dark, substantial green, with clear indications of laterals at the 

 first-made shoot joints, the sap at all the lower wounds had 

 now dried up. The weather of this month was mild for the 

 month of February, the greatest cold was 22°, the medium of 

 heat was 46", and of cold 34 ^^V, with only -|-J\, of rain. 



On the 20th of February, the vine which was neither pro- 

 tected from rain nor excited, began to droop and stagnate, 

 the shoot ends became brown, downy, and sickly altogether ; 

 no sap ever exuded outside the wall ; the roots never showed 

 ihe least signs of vegetation ; the three bunches of grapes 

 shown upon it curled up and withered away. 



On the 1st of March, I removed both vines into another 

 pine stove; the excited vine continued health}', and ripened 

 the bunch of grapes left upon it. 



