BY THE PRESIDENT. 119 



The Brick Earths of the neighbourhood would also repay inves- 

 tigation. In some of these there are laminated beds of clay 

 between which impressions of leaves may be found ; they are 

 extremely rare however, and it is difficult to say whether those 

 beds containing leaves belong to Tertiary times, or to a period when 

 the brick earth itself was deposited. 



There is only one other geological point upon which I will ad- 

 dress you ; and I hope you will excuse me for dwelling more on 

 geology than other parts of Natural History, as I feel myself more 

 at home in that domain than in some of the others. There is a 

 geological deposit essentially known as belonging to Hertfordshire 

 — the Hertfordshire plum-pudding stone. At the present time 

 there are not more than one or two places known where it can be 

 met with in the actual position in which it has been formed. There 

 is one place near Eadlett where you will find the Woolwich and 

 Reading beds (which are below the London Clay) cemented 

 together with flinty cement into a band of pudding stone. This is 

 in its original position, with the upper portion worn away as if by 

 the action of ice or some strong abrading material over it. It 

 would be interesting to see if we could find upon any rock of that 

 character in position, those striations or ice-markings which are so 

 characteristic of local glaciers. 



With regard to Botany, I must at the outset say that I know 

 very little about it. But there are several points which it appears 

 to me may be very well investigated by those better acquainted 

 with the subject than myself; and one of these is the connexion 

 of the geology of the country with the plants found on its surface. 

 Mr. Pryor has made some suggestions with regard to dividing the 

 county into certain districts, more especially according to the river- 

 basins ; but I think it also desirable for botanists to notice, not 

 only the nature of the sub-soil as shown on the geological map, 

 but the drift, or sui-face soil that comes above it. There is no 

 doubt that there is a very intimate connexion between the Botany 

 of a district and its geological formation ; in fact, geologists not 

 unfrequently are led to discover outliers of clay from the woods 

 growing upon them. In olden times the London Clay was not 

 so easily di'ained as at present, and in consequence portions of it 

 existing in Chalk areas, being too heavy for cultivation, were left as 

 sites for woods. It is generally the case that wherever there is a 

 Tertiary outlier, there is a wood upon it ; and thus the outlines of 

 the countiy are such as in many cases to suggest to geologists the 

 spots where Tertiary outliers may be looked for. 



