EXTRACTS OF PROCEEDINGS. 



xix 



sometimes more or less twisted, seem to have little or no power of 

 motion, and they are destitute of those regularly formed, closely 

 packed cells called palisade cells. In the Silver Firs, on the other 

 hand, the leaves are more or less flattened, so that they have a dis- 

 tinct upper and lower surface ; those on the under surface of a shoot 

 are twisted so as to bring them into the same horizontal plane as 

 the upper ones. Moreover, they often overlap one another, and in 

 this way would obstruct the passage of the light to the lower. This 

 is obviated by the circumstance that the uppermost leaves are 

 usually shorter than the subjacent ones, so that less of the surface 

 of the latter is covered. In some cases, too, the upper leaves, in- 

 stead of spreading horizontally, are so placed as to be parallel to the 

 long axis of the shoot and at right angles to the lateral leaves. A 

 still more effective means of securing access of light to the lower 

 leaves, and at the same time of exposing the lower surfaces, on 

 which the majority of the stomates are placed, to the influence of 

 light and heat, is secured by the power of elevation and depression 

 which the leaves of the silvers have. This is so marked in some 

 cases, as in A. Nordmanniana, that when the leaves are thus up- 

 lifted so as to show their glaucous under-surface, the whole of the 

 tree is milky-white in appearance. In these flat-leaved silvers the 

 palisade cells are usually found forming a distinct layer beneath 

 the upper surface. 



The late Mr. Wilson Saunders, — It was unanimously agreed that 

 the President be requested to address a letter of condolence to the 

 family of the late Mr. W. Saunders. Mr. Saunders was one of 

 the original members of the committee, took great interest in its 

 proceedings, and to the last contributed notes of observation and 

 specimens. The committee has to regret the loss of one of its 

 staunchest and most useful members. 



