xliv Journal of Proceedings.
which the spiny variety (Ononis campestris) only prevails thereabouts.
The common elm at this locality is a remarkably small-leaved form, the
leaves on young and vigorous shoots being diminutive; and during the
whole day Quercus pedunculata was the only form of oak we met with.
Plunging into the luxuriant vegetation of a rough sloping bank of waste-
land by a green lane we speedily came upon much of interest; quantities
of flea-bane (Pulicaria dysenterica), meadow-sweet (Spiraea Ulmaria) with
its characteristic gall, the result of the "house holdings" of a small gall-
gnat called Cecidomyia Ulmaria, an oak stump with its twigs much
affected with both the Devonshire or marble gall (the work of Cynips
Kollari) and the very curious artichoke gall (Aphilothrix gemmae, L.,
C. fecundatrix, Hart.), the result of the distortion of the leaf or flower-bud
of the oak by the insect. Other plants noticed were some fine examples
of thistles (Onopordon Acanthium- and Carduus palustris), red campion
(Lychnis diurna), tufted vetch (Vicia cracca), willow herbs, and St. John's
worts. The handsome teasels (Dipsacus sylvestris) with several pairs of
connate leaves, forming pitchers crammed with animal matter, suggested
some remarks on accidental and purposive structures; whilst as they were
just in flower, they also illustrated the artificial nature of the classification
of inflorescences into centrifugal (in which the central flower opens first)
and centripetal (in which the order of development is the reverse, the
lower flowers opening first); in the teasel tribe (Dipsacaceae) many
examples occur, as in D, sylvestris, of a combination of both forms of
development. Convolvulus sepium, generally preferring cultivated ground,
was, however, plentiful, as also was the bittersweet (Solanum Dulcamara) ;
whilst in fruit were noted the pepper wort (Lepidium campestre), cuckoo-
pint (Arum maculatum), black bryony (Tamus communis), and cleavers
(Galium Aparine), the abundance of which last afforded a practical
exemplification of one mode of seed-dispersal, the curious little rough
fruit with its hooked bristles clinging in hundreds to our clothes as we
forced our way through the thick herbage. The large compound umbels,
hollow or "fistular" stems, and pinnately-divided leaves with large basal
sheaths?, of fine specimens of Angelica sylvestris (suggesting to our
entomologists larva of Eupitheciae) and the cow-parsnip (Heracleum
Sphondylium) illustrated the order Umbellifera. We leave the "siding"
to pass through Steward's Green, as it is called,—a long green lane, which
seems to possess some interest to the entomologist and botanist. Here
we encountered the centaury (Erythraea centaurium), Hypericum hirsutum,
and a remarkably small-flowered Epilobium parviflorum, which were
"bagged" previous to the "interval for refreshment." The bittersweet
was luxuriating in a pond by which stood some sycamores, free from the
fungus Phytisma, and covered with their winged "samaras." The
"Theydon Oak," growing by a pond not far from the Inn, is now a mere
wreck, and was estimated at twenty-six feet girth and to be not less than
three centuries in age. The party then plunged into Theydon Garnon
or Coopersale Forest, dense with holly and hornbeam, and apparently