The Naturalist on the Thames | Page 8

spikes of flower were standing out of the water like orchids, while the bladders with their trapdoors were employed in catching and devouring small tadpoles. There is something quietly horrible about these carnivorous plants. Their bladders are far too small to take one in whole, but catch the unhappy infant tadpoles by their tails and hold them till they die from exhaustion.
The bank flora of the Thames is nearly all the same from Oxford to Hampton Court, made up of some score of very fine and striking flowers that grow from foot to crest on the wall of light marl that forms the bank. Constantly refreshed by the adjacent water, they flower and seed, seed and flower, and are haunted by bees and butterflies till the November frosts. The most decorative of all are the spikes of purple loose-strife. In autumn when most of the flowers are dead the tip of the leaf at the heads of the spikes turns as crimson as a flower. The other red flowers are the valerian, in masses of squashed strawberry, and the fig-wort, tall, square-stemmed, and set with small carmine knots of flower. In autumn these become brown seed crockets, and are most decorative. The fourth tall flower is the flea-bane, and the fifth the great willow-herb. The lesser plants are the small willow-herbs, whose late blossoms are almost carmine, the water-mints, with mauve-grey flowers, and the comfrey, both purple and white. The dewberry, a blue-coloured more luscious bramble fruit, and tiny wild roses, grow on the marl-face also. At its foot are the two most beautiful flowers, though not the most effective, the small yellow snapdragon, or toad-flax, and the forget-me-not. This blue of the forget-me-nots is as peculiar as it is beautiful. It is not a common blue by any means, any more than the azure of the chalk-blue butterflies is common among other insects. Colour is a very constant feature in certain groups of flowers. One of these includes the forget-me-nots, the borage, the alkanet, and the viper's bugloss, which keep up this blue as a family heirloom. Others of the tribe, like the comfrey, have it not, but those which possess it keep it pure.
The willows at this time are ready to shed their leaves at the slightest touch of frost. Yet these leaves are covered with the warts made by the saw-flies to deposit their eggs in. The male saw-fly of this species and some others is scarcely ever seen, though the female is so common. The creature stings the leaf, dropping into the wound a portion of formic acid, and then lays its egg. The stung leaf swells, and makes the protecting gall. It is difficult to say when "fly," in the fisherman's use of the term as the adult insect food of fish, may not appear on the water. Moths are out on snowy nights, as every collector knows, and on any mild winter day flies and gnats are seen by streams. In the warm, sunny days of late September, numbers of some species of ephemerae were seen on the sedges and willows, with black bodies and gauzy wings, which the dace and bleak were swallowing eagerly, in quite summer fashion. The water is now unusually clear, and as the fish come to sun themselves in the shallows every shoal can be seen.
Among the typical Thames-valley flowers, all of which would be the better for protection, are the very rare soldier orchis (_Orchis Militaris_) and the monkey orchis (_Orchis Simia_), the water-snowflake, the hottonia, or water-violet, the water-villarsia, more elegant even than the water-lilies, the flowering rush, with a crown of bright rose-pink flowers. The two orchids named are very interesting plants. Of the monkey orchis Mr. Claridge Druce says in his "Flora of Oxfordshire" that it has become exceedingly scarce, not so much from the depredations of collectors, but from the fondness of rabbits for it and the changes brought about by agriculture. The soldier orchis is very rare indeed; both are only found in a few woods in the Thames valley, and possibly in Kent. The bladderworts fade instantly, and are not much interfered with, and though the fritillaries are picked for market, the roots are not dug up because that would injure the meadow turf in which they grow, and business objections would be raised.

INSECTS OF THE THAMES
Except among the select few, generally either enthusiastic boys or London mechanics of an inquiring mind, who keep fresh-water aquariums and replenish them from ponds and brooks at "weekends," few persons outside the fancy either see or know much of the water insects,[1] or are aware, when floating on a summer day under the willows in a Thames backwater, of the near presence of thousands of aquatic creatures, swift, carnivorous, and pursuing, or feeding greedily on