772 



of Britain. I am happy to say that so far as I am concerned, the new 

 locality is perfectly genuine. 



It would only be right that those who naturalize rare plants, should 

 give publicity to the fact ; and should I ever do so, I shall not 

 fail to make the readers of the ' Phytologist ' acquainted with the 

 particulars. 



George G. Mill. 

 Kensington, Feb. 1847. 



Report of Mr. Hincfc's paper " On the causes of disjunctions of 

 Vegetable Substance, especially those which are horizontaV* 



" After some preliminary observations on the subject of disruptions 

 in general, the author briefly notices certain cases of vertical disrup- 

 tion, and then proceeds to the more immediate object of his paper, 

 the horizontal separation of vegetable substance by natural means. 

 This, he observes, may take place in the axis itself, or in any of the 

 organs connected with it at their points of attachment, as in the fall 

 of the leaf, of sepals and petals, of entire flowers and fruits, and in 

 the separation of such buds as form caulinary bulbs ; or it may occur 

 at some other part of the organ, a portion separating from the rest, or 

 the whole breaking up into pieces. Every such separation, he argues, 

 must depend on one of the three following causes: 1. on a stoppage 

 of the circulation from ligature; 2. on unequal rapidity of growth of 

 the two parts ; or 3. on the confinement within coherent envelopes 

 (which do not admit of extension) of a portion of the axis or of some 

 growing part, so that the force of growth bursts the envelope, carry- 

 ing ofi" its upper portion. These general rules he then proceeds to ap- 

 ply to the explanation of particular cases. 



" Of stems usually termed Articulate, some, such as those of Kleinia 

 articulata, have no tendency to disruption at the supposed joint, 

 which is merely the commencement of a new branch. In the misletoe, 

 on the other hand, the author believes that the tendency to divide at 

 the bases of the branchlets may be consequent on the dichotomous 

 structure, which causes a pressure equivalent to a ligature at the point 

 of division. 



* Eead before tbe Linnean Society Dec. 16, 1845. 



