512 Principles of Landscape- Gardening 



endosmose. Some think the fact, that imbibition is sometimes 

 found to have the strongest current from the denser to the lighter 

 fluid, a proof that some other power than endosmose is con- 

 cerned in imbibition ; others say it is the same phenomenon 

 modified by some peculiarities of the fluids themselves, or of the 

 vessels they circulate in. In animals at least, absorption, if pro- 

 duced by endosmose, must, it is said, be held in check by vita- 

 lity preventing the mingling of fluids, and causing it to act in 

 some cases and cease in others. 



The fact of the existence of an exosmose as well as endos- 

 mose current seems to infer the truth of the theory of the excre- 

 tions by the roots of plants, now generally admitted by most 

 physiologists and chemists, though still doubted by some very 

 eminent men. The experiment of Dr. Madden, in which, having 

 washed the roots of a plant of groundsel, and introduced one half 

 of them into a phial containing water mixed with ulmate of 

 ammonia, and the other half into a phial of pure water, he found 

 at the end of a few days an excretion of a gummy-looking sub- 

 stance in the pure water, seems to confirm and corroborate those 

 of Macaire. The fungi found so abundantly on the roots of some 

 plants, as those of Scotch fir, spruce, oak, &c., must be fed by 

 morbid excreted matter from the roots, probably of a nitro- 

 genous nature, as nitrogen forms so large a proportion of these 

 plants. 



Besides capillary attraction and vital contractility, which as- 

 sist the power of endosmose by furnishing the conditions needed, 

 of removing the thinner imbibed fluid and supplying its place 

 with denser sap, it is thought by many, from the peculiar force 

 with which imbibitions take place in the living spongiole, as com- 

 pared with the phenomena of endosmose in dead membranes, 

 that a peculiar ^dtal force is also concerned, which may very 

 likely be the case. Besides the absorption by the roots, water 

 and its contents are absorbed by other parts of plants, especially 

 by the under side of the leaf. 



(To be continued.) 



Art. II. The Principles of Landscape- Gardening and of Landscape- 

 Architecture applied to the Laying out of Public Cemeteries and 

 the Improvement of Churchyards ; including Observations on the 

 Working and General Management of Cemeteries and Burial- 

 Grounds. By the Conductor. 



{Continued from p. 494.) 

 IX. Lists of Trees, Shrubs, and perennial herbaceous Plants, 



ADAPTED FOR CEMETERIES AND CHURCHYARDS. 



In the following selections we have chiefly included plants that are quite 

 hardy, and that, when once properly planted and established, will grow in turf 



