6 Dr. H. Franklin Parsons on the 
the tissues of the caterpillar, and when the latter las buried 
itself in the ground it dies, and the fungus sends up its fruc- 
tification in the form of a slender orange club, the stalk of 
_ which can be traced down into the body of the dead insect. 
Cronam Hurst.—Area 80 acres; altitude 288-477 ft. This 
hill is an outlier of the Oldhaven pebble beds, surrounded on all 
sides by chalk, the intervening Woolwich Beds and Thanet Sand 
being very thin, and almost wanting; hence, in the absence of 
an impermeable bed to throw out the water from the gravel, 
there are no springs or wet places. The south slope of the hill 
is in places so steep that no vegetation can find a foothold, and 
the pebble gravel is left bare. The summit of the hill is open 
heathy ground, but the sides and base are wooded. ‘The flora 
in the woods at the base of the hill on the chalk is markedly 
different from that on the pebble beds higher up. Among the 
species found at Croham Hurst are the whortleberry and the lily 
of the valley; though the latter appears very seldom to flower 
there. The rare ground-pine (Ajuga chamepitys) grows close to, 
if not actually within, the Hurst. 
Hayes Common and West WickHam Common together form 
one open tract, being only separated from one another by an 
unfenced road. ‘This tract has an area of 200 acres, and varies 
in altitude from some 230 to 400 ft. It rests on the pebble beds, 
which end in a steep escarpment on the south and west. On 
the top of West Wickham Common ait its south-west corner are 
some ancient barrows and entrenchments, possibly marking the 
site of a battle which is said to have taken place at Addington 
between Hengist and the British. A noticeable feature is the 
fine group of venerable oaks on the steep north-west slope of 
West Wickham Common, the ground beneath which in spring 
is carpeted with bluebells. Among plants met with at Hayes 
and West Wickham Commons are Saaifraga granulata, the 
climbing fumitory (Corydalis claviculata), Menchia erecta, and 
Trifolium glomeratum. The butcher’s broom (Ruscus aculeatus) 
grows Close to but not actually on the common. 
Krston Common.—Area 55 acres; altitude 400-520 ft.; is 
situated on the north slope of the Oldhaven pebble beds, and is 
intersected by two valleys, one of which is occupied by a boggy 
piece of ground, and the other ‘by artificial ponds. Keston 
Common has perhaps the most interesting flora of any of the 
commons neai Croydon. In the boggy ground are found the 
sundew (Drosera rotundifolia), the marsh pennywort, the bog 
violet, the bog asphodel, Carduus pratensis, and several species 
of Sphagnum; while in the ponds grow the arrow-head, the small 
bur-reed, Scirpus fluitans, and several other aquatic plants— 
whether planted or brought by birds, I cannot say. In 1894 I 
saw a single plant of the butterwort (Pinguicula vulgaris) at 
