I myself not long ago met with an appearance which bore a much closer resemblance to drops of blood than this, and which yet was referrible to a widely different origin. In the neighbourhood of Ashburton, in Devon, a quarter of a mile or so from the town, there is a shallow horse-pond, the bottom of which consists of an impalpable whitish mud, much indented with hoof-holes and other irregularities. In these, the water being dimly clear from settlement, I observed what looked exactly like blood, in numerous patches, the appearance being as if two or three drops of blood had fallen in one spot, half-a-dozen in another, and so on. The colour was true, and even when I alighted, and looked carefully on the spots, they had just that curdled appearance that drops of blood assume when they fall into still water. But there appeared on minute examination a constant intestine motion in each spot, which caused me to bring my eye closer, when I discovered that I had been egregiously deceived. Each apparent drop of blood was formed of a number of slender worms, about as thick as a hog's bristle, and an inch and a half long, of a red hue, which protruded the greater part of their length from the mud, in a radiating form, each maintaining a constant undulatory movement. There were more or fewer centres of radiation, the circles frequently interrupted by, and merging into, others, just as drops of blood crowded together would do. On the slightest disturbance the little actors shrank out of sight into the soft mud; but by scooping up a little of this I contrived to get a number of them into a phial, which, as the sediment settled, were seen at the bottom playing as if in their pond. On examination of the specimens with a microscope I found them to be minute Annelids, such as I have described, apparently of the genus _Lumbriculus_ of Grube, with two rows of bristle-pencils, and two bristles in a pencil. The body was transparent and colourless, and the red hue was given by the great and conspicuous longitudinal blood-vessels, and by the lateral connecting vessels, which viewed sidewise took the form of loops. The animals soon died in captivity, but I kept some for three or four days alive.