36 Analysis of the MCcanique Celeste of M. La Place, 



winter, is again called into action to feed the buds, which 

 elongate into parts ot" the stems of the future plants in the 

 spring, fibrous roots are emitted from the bases of these 

 stems, whilst buds are generated at the opposite extremities, 

 as in the cases I have mentioned respecting trees. 



Many naturalists* have supposed the fibrous roots of aM 

 plants to be of annual duration only ; and those of bulbous- 

 and tuberous-rooted plants certainly are so : as in these Na- 

 ture has provided a distinct reservoir for the sap which is to- 

 form the first leaves and fibrous roots of the succeeding sea- 

 son ; but the organization of trees is very difierent, and the 

 alburnum and bark of the roots and stems of these are the 

 reservoirs of their sap during the winter f. When, however, 

 the fibrous roots of trees are crowded together in a garden- 

 pot, they are ofen found lifeless in the succeeding spring; 

 but I have not oljscrved the same mortality to occur, in any 

 degree, in the roots of trees when growing, under favourable 

 circumstances, in their natural situation. 



I am prepared to offer some observations on the causes 

 which direct tlie roots of plants in search of proper nutri- 

 ment, and which occasion the root of the same plant to as- 

 sume difTcrcnt forms under different circumstances; but I 

 propose to make those observations the subject of a future 

 con)munication. I am, my dear sir, 



with great respect, your much obliged, &c. &c. 

 Thomas And. Knight. 



Elton, Dec. '22, 1808. 



VI. Anahjus of the Mecanique Celeste of M. La Pi^ce. 

 By M. BioT. 



[Continued from vol. xxxiii. p. 476'.] 



J. HK autiior is afterwards occupied with the determination 

 of the motions of the heavenlv bedies by successive approxi- 

 niations. In the theory of these motions the action of the 

 perturbating forces only obliges us to add some small terms 



• M. Mirbcfs TraitQ d' AnaUmie, &i.. &c. Dr. Smith's Introduction to 

 Botany. 



-|- Philosopliical Transactions for 1805. 



