32 
THE ESSEX NATURALIST. 
a short formal meeting of the Club was held, with Miss E. Willmott, 
F.L.S., V.M.H., member of Council, in the chair (our President having 
had to leave the party somewhat earlier), when Mr. John H. B. Jenkins, 
ol Glenmore, Tavistock Road, Snaresbrook, was elected a Member, and 
three nominations for membership were announced by the Acting Hon. 
Secretary. 
While waiting for the return train, many of the visitors entered Epping 
Church, and inspected the elaborate gilt organ-front and the beautiful 
modern rood-screen and other fittings of this excellent example of modern 
Gothic architecture. 
FIELD MEETING AT NORTHWOOD AND RUISLIP. 
(488th MEETING.) 
SATURDAY, 8tH JUNE 1918. 
A Field Meeting was arranged in this charming district of Middlesex 
on this date to enable Members to study the local botany and geology 
under the leadership of Mr. Robert Paulson, F.L.S., and Mr. William 
Whitaker, B.A., F.R.S., F.G.S. respectively. 
The party, to the number of nearly 30, met at the Pinner and Hatch 
End station of the Bakerloo extension to Watford at 11.15 o’clock, and 
made its way across fields radiant with buttercups to Pinner Hill, crossing 
en route the old British shallow earthwork known as Grimm’s Dyke, which 
marks, in all probability, a pre-Roman tribal boundary, “ herborizing ” 
and entomologizing being indulged in by the way. 
On Pinner Hill, utilising an extensive view southwards over the lower 
country, Mr. Whitaker gave a short account of the geological features 
of the neighbourhood, pointing out that, on its passage from the station, 
the party had crossed an inlier of Reading Beds in a mass of London Clay. 
Pinner Hill is itself of London Clay, capped by high-level “ Plateau 
Gravel,” derived probably from once-overlying pebbly Bagshot Beds, 
which have long since been entirely denuded away, though beds of similar 
age still cap Harrow Hill to the south. 
Mr. Paulson then took up the theme by calling attention to the effect 
on the tree-flora of the different geological formations. He pointed out 
that, in woods on the lower London Clay grounds, Ouercus pedunculata 
is the dominant form of Oak, with Hazel association, whereas, on the 
hill slopes and higher grounds, Quercus sessili/lora becomes the characteristic 
form, and is associated with Hornbeam, Beech, and Birch. 
Skirting the growing town cf Northwood, the geologists of the party 
examined a small section in the Reading Beds on the golf-links, just to 
the south of the town, which showed a fine pale-yellow quartz sand without 
pebbles. Meanwhile, a number of interesting plants was noted bv the 
botanists on the adjoining ground, including again Mconcilia erecici, which 
had been noted at Epping on the last excursion. 
The most important botanical observation of the day was made at 
Ruislip Reservoir. The level of the water was low, the reservoir having 
been partly drained recently, and the margin exhibited a distinct, broad, 
orange-coloured zone, following the contour of the water along the entire 
length of the reservoir, for nearly { mile, and strikingly evident from a 
