XVIU PBOCEEDINGS OF THE 



Mr. J. Hopklnson oxliibited livinj? plants of Bentaria hulhifera 

 (coral root) from. Hed Heath, in flower ; and also, under the 

 microscope, one of the axillary bulbs which produce new plants by- 

 falling to the ground and there growing — the coral root being 

 usually propagated in this way, as the pod seldom ripens. 



Living plants of Bentaria hulhifera, from the same locality, were 

 also exhibited by Mr. W. L. Smith. 



Field Meetixg, 29(rH M.vy, 1875. 

 CoLNE Valley "Wateu "Works, Bushey Kilx, and Watford Heath Kiln. 



As the weather had prevented the route arranged for the 1st of 

 May being then taken, it was decided upon for this occasion, and 

 a party of about fifty ladies and gentlemen, many of whom were 

 members of the Geologists' Association, who had been invited to 

 take part in this meeting, assembled at Bushey Station at three 

 o'clock. 



The Chalk-pit near the station was first visited. A good section 

 of the Upper Chalk is here seen, and overlying it a bed of flint- 

 pebbles from the Woolwich and Reading series proved the former 

 presence of this formation. This bed completely thins out in the 

 pit, and is succeeded by clay-drift and sandy gravel (terrace-gravel), 

 which repose, in other parts of the pit, immediately on the Chalk. 



At the Colne Valley Water Works, adjoining this pit, the party 

 were received by Mr. William Verini, who gave an account of 

 the sinking of the well, which he stated had been excavated to a 

 depth of 70 feet, or to 108 feet above ordnance datum, abundance 

 of water having been obtained. Professor Morris here stated that 

 the Chalk is one of our best reservoirs, when exposed over a con- 

 siderable area absorbing a large amount of rainfall, which, in more 

 impervious rocks, instead of sinking, would at once form rivers 

 on the surface. The water is retained in the Chalk by imper- 

 meable beds of clay — the Gault clay — below it, and in boring an 

 underground channel is sometimes tapped. 



Leaving the Water Works, — which when complete will supply 

 Bushey, Stanmore, Edgware, and other places, with water from the 

 Chalk, softened by what is called the " lime process," — the party 

 proceeded to Bushey Kiln, where a .section of the higher beds of 

 the Woolwicli and Reading series, and of the basement-bed of the 

 London Clay, is exposed. 



Crossing then the fields to Watford Heath Kiln, several plants 

 were collected, and the ragged Robin (Lychnis Flos-cuculi J , one of 

 the species in the Meteorological Society's list, was seen to be just 

 coming into flower, fully a week later than usual. 



At Watford Heath there is a more extensive section of the beds 

 seen at Bushey — the Woolwich series being visible almost to its 

 junction with the ('lialk, and several feet of tlie London Clay, 

 above its basomont-bed, being exposed. Here Professor ^lorris 

 stated that we were just on or near the edge of the London Basin, 



