64 OBSERVATIONS ON THE GROWTH IN DIAMETER OP 



III. — Abstract, Sc. of a Paper entitled " Observations on the 

 Groioth in Diameter of Dicotyledonous (Exogenous) Sterns.'^ 

 By D. Oliver, Jun. 



[Read, November 15th, 1855.] 



This paper was the result of an inquiry suggested to John 

 Thornhill and myself by the recent publications of Auguste Tre- 

 cul, in the "Annales des Sciences Naturelles/' * on the relations 

 subsisting between the newly-formed woody fascicles of a Dico- 

 tyledon and the growing points or buds situated above them at 

 the time of their formation, bearing especially upon the views 

 propounded by Gaudichaudt and others. Although some of 

 these papers were the result of investigations more especially 

 directed to the settlement of the theoretical questions involved 

 in these relations, and our experience enables us, I believe, to 

 add, with some degree of final certainty, yet other minor and 

 collateral observations were attached, which also offered to the 

 Vegetable Anatomist no slight interest. I shall endeavour 

 briefly to enumerate the principal points which engaged our 

 attention ; our results, I think we may say, were confirmatory 

 of those obtained by Trecul. 



Viewed apart from notions as to the more or less individualised 

 character of portions of the plant — for example, of the cell, of 

 leaves, or of the "sprout" — the phenomena involved in the incre- 

 ment of the vegetable structure, in our present instance, of the 

 Dicotyledon, have been, until within recent years, much misunder- 

 stood ; the true anatomical and physiological characteristics of the 

 cambium as an instance, which so intimately concern an investiga- 

 tion of this kind. J This (the cambium) we alluded to at some 

 length, with the suggestion that the term should perhaps now be 

 discarded; not that it is insufficiently expressive and appropriate, 

 rather from its association with the idea of a general, mucilagin- 

 ous, semi-fluid investment of the alburnum, so long a time 

 indefinitely and incorrectly considered as such, to separate 



* Annales des Sciences, 3me Ser., xvii. 250 ; xviii, 14 ; xix. 63, 157, 257 ; xx. 197. 



■f L'Organographie, &c. des V^gtJtaux, p. 13, &c. 



X Jussieu, Cours Clomentaire de Botanique, p. 52 and 55. 



