Keegan : The Wych Elm. 2 i 



terminates in June, and new buds are thereupon formed. The 

 flowering-, too, is very precocious, and the fruit rapidly matures 

 and vegetates the same season. Hence from the latter weeks 

 of June there is nothing- to do, as it were, for the org-anic 

 principles ready formed and apt for chemical transformations, 

 and therefore their weig^hts or percentag-es in the fresh leaf, etc., 

 seem to underg-o little change from the beginning of July till the 

 autumnal fall in mid November. A somewhat similar physio- 

 logical condition of things occurs in a few other of our indigenous 

 forest trees, but as regards the increase in the percentage of 

 ash and of silica as the life of the leaf progresses, the Wych Elm 

 has no compeer. Thus, on 5th June, in the not-as-yet full-sized 

 leaves I found 9 per cent, of ash in dry having 9.4 silica therein, 

 and on i6th November the corresponding figures amounted to 

 i6'8 and 28'8 respectively. The general explanation of this fact 

 is, as expressed by Palladin, that ' it is on the quantity of water 

 vapourised by plants that depends in a great measure the 

 entrance and the distribution in the plant of silica, lime,' etc. 

 The enormous accumulation of silica in the Elm leaf is the 

 result of the action of the living tissues on the perishing or 

 dying tissues with which they are connected. ' Between the 

 time,' says M. Emile Mer, 'when a tissue in contact with living 

 tissue commences to perish and that when it dies it dries a little, 

 and in proportion as this water is evaporated it is replaced by a 

 drainage of substances,' etc. The physiological condition of 

 the leaf admits, so to speak, of a kind of demise almost from 

 the first — a sort of drying, not perhaps of the entire organ, but 

 especially of its external tissues ; and the water thereby lost is 

 replaced by silica which, copiously supplied by special soil, 

 proceeds from the living parts towards the dermal appendages, 

 especially of the upper surface. 



mAMiWALS. 



White Mole in Lincolnshire. — 'A White Mole, taken by 

 a member (of the Spalding Society) at Cowbitt, in his garden in 

 this parish. Present to the Museum. A spot of black hairs 

 round each eye and a black tail.' ' Antiquities in Lincolnshire,' 

 being the Third volume of the ' Bibliotheca Topographica 

 Britannica ' (Nichols), 1790. — E, Adrian Woodruffe-Peacock. 



1906 January i. 



