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dictate but the ' Phytologist' has a reputation to support, and can- 

 not afford to criticise at random. It often, we may say generally, 

 happens that the reviewer in these pages knows tenfold more of the 

 subject than the author he reviews : in the present it is not so, and we 

 will not assume a knowledge we do not possess. The editorial obser- 

 vations will therefore only serve to connect quotations, which we 

 hope will induce our readers to possess themselves of the volume 

 whence they are extracted. 



Mr. Rainey begins thus. 



" 1. The fluid which vegetables imbibe from the soil on which 

 they grow is generally called the ascending or crude sap. 



" 2. The crude sap, after having been elaborated in the vessels of a 

 plant, and fitted for the development and production of new parts, is 

 called the elaborated sap. 



" 3. The direction taken by the crude sap is always from the root 

 towards the branches, whilst that of the elaborated sap may be either 

 upwards or downwards, according as the process of elaboration is 

 most active in the vessels of the roots, or in those of the leaves, 



" 4. Besides the movement of these fluids, there is a distinct and 

 separate motion of that within the cells, denominated ' Cyclosis,' in 

 which case the contents of one cell move independently of those in 

 the adjoining cells : this phenomenon, being a local and not a general 

 operation, does not come under the consideration of the ascent and 

 descent of the sajx 



" 5. Before a precise explanation can be given, or a correct notion 

 obtained, of the cause of the ascent of the crude sap, or of the ascent 

 and descent of the elaborated fluid, the structures which each of these 

 fluids traverses in its passage from one extremity of a plant to another, 

 must be accurately determined and clearly demonstrated. 



" 6. The following experiments have been instituted and performed 

 for the purpose of satisfactorily determining these points, of showing 

 first, that the crude sap ascends along a tissue which chiefly exists 

 between the cells, but which enters also into the structure of the more 

 solid and permanent parts of a plant, and secondly, that the elaborat- 

 ed fluid, both in its descent and ascent, passes along the ducts and 

 spiral vessels. 



" Experiment to show the structure occupied by the crude sap in 

 its ascent and diffusion through all parts of a plant. — 7. The inferior 

 extremity of a long branch of the Valeriana rubra was placed in an 

 aqueous solution of bichloride of mercury, a short time after it had 

 been removed from the plant, and its leaves had slightly shrunken 



