THE ESSEX FIELD CLUB. 
117 
belt of the characteristic Oak-Ash woodland was then examined. The 
principal features of this were the absence of the Oxlip (Primula elatior), 
which is so marked a feature of the woodland on the east of the Cam, 
and the characteristic associations of Carex pendula and Air a. Attention 
was also called to the great abundance of the bramble Rub us ccesius, 
and the absence of Rubus fruticosus was commented upon. 
Leaving the wood, the party passed across the clay waste where the 
different plant associations were examined. 
(1) The open flora of the most barren parts with 7 araxacum dens 
leonis , Fragaria vesca and Hypericum hirsutum , dominants. 
(2) The Lotus corniculatus association on slightly richer soil. 
(3) The invasion belts of Brachypodium, Rubus, etc., from the 
woodlands. 
(4) The damp hollow associations of Centaurea nigra and Arrhena- 
therum elatus which culminate in a ditch zone of Spiraea ulmaria. 
During a short rest, Mr. L. F. Newman, of the School of Agriculture, 
Cambridge University, gave an address on the chemistry and physical 
character of the local soils from the agriculturist’s standpoint, dwelling 
on the great importance of the size of the soil particles upon plant life. 
He pointed out that the extreme fineness of the clay particles was the chief 
reason for the difficult nature of the boulder clay. In dry weather the 
particles were baked together into a hard crust, which effectually kept 
out light and air and prevented plant development. 
Crossing the waste, specimens of Blackstonia perfoliata, Hieracium 
pilosella and Centaurium umbellatum and other chalk-flowers were gathered- 
On the top of hill specimens of the Bee and Spotted Orchids and Tway- 
blade were found, while in a belt of woodland to the north specimens of 
the Bird’s-nest and Butterfly orchids were seen. In this wood the char¬ 
acteristic Melampyrum cnstatum occurs and also a few plants of Bracken, 
which is rare in this district. 
Leaving the wood, the party then passed through a waste area of con¬ 
siderable age which had reverted to White-thorn scrub. Here many 
Bee Orchids were seen. 
Lower down the hill the presence of Helianthemum was noted, 
showing the presence of the chalk outcrop. 
Later in the day Lamium galeobdolon was obtained in a wood behind 
Chrishall Church- 
At one point the highest land of the county was crossed, the elevation 
being just under 500 feet above sea-level, and eventually the excursionists 
made their way to the brakes at Bilden End. 
Chrishall Church was visited and the fine canopied brass to Sir John 
•de la Pole and lady, 1370 A.D., and other monuments were inspected, and 
the party then drove through Chrishall and Elmdon, glorious views over 
Cambridgeshire and the Fen Country being obtained from the high ground. 
At Elmdon Bury, tea had been provided on the lawn by Mr. J. F. Wilkes, 
after which a short visit was paid to the ancient entrenchment from which 
the property takes its name, and to the church. Hearty votes of thanks 
were passed to Mr. and Miss Wilkes for their hospitality, and the great 
interest they had taken in the day’s proceedings, and the company then 
