The pond in the piece of planting, though as unsightly a little patch of water as might be, was, I found, a greatly richer study than the dark rivulet. Mean and small as it was--not larger in area inside its fringe of rushes than a fashionable drawing-room--its natural history would have formed an interesting volume; and many a half-hour have I spent beside it in the heat of the day, watching its numerous inhabitants--insect, reptilian, and vermiferous. There were two--apparently _three_--different species of libellula that used to come and deposit their eggs in it--one of the two, that large kind of dragon-fly (_Eshna grandis_), scarce smaller than one's middle-finger--which is so beautifully coloured black and yellow, as if adorned by the same taste one sees displayed in the chariots and liveries of the fashionable world. The other fly was a greatly more slender and smaller species or genus, rather _Agrion_; and it seemed two, not one, from the circumstance, that about one-half the individuals were beautifully variegated black and sky-blue, the other half black and bright crimson. But the peculiarity was merely a sexual one: as if in illustration of those fine analogies with which all nature is charged, the sexes put on the _complementary_ colours, and are mutually fascinating, not by resembling, but by _corresponding_ to, each other. I learned in time to distinguish the disagreeable-looking larvæ of these flies, both larger and smaller, with their six hairy legs, and their grotesque formidable vizors, and found that they were the very pirates of the water, as the splendid insects into which they were ultimately developed were the very tyrants of the lower air. It was strange to see the beautiful winged creature that sprang out of the pupa into which the repulsive-looking pirate had been transformed, launch forth into its new element, changed in everything save its nature, but still unchanged in that, and rendering itself as formidable to the moth and the butterfly as it had been before to the newt and the tadpole. There is, I daresay, an analogy here also. It is in the first state of our own species, as certainly as in that of the dragon-fly, that the character is fixed. Further, I used to experience much interest in watching the progress of the frog, in its earlier stages from the egg to the fish; then from the fish to the reptile fish, with its fringed tail, and ventral and pectoral _limbs_; and, last of all, from the reptile fish to the complete reptile. I had not yet learned--nor was it anywhere known at the time--that the history of the individual frog, through these successive transformations, is a history in small of the animal creation itself in its earlier stages--that in order of time the egg-like mollusc had taken precedence of the fish, and the fish of the reptile; and that an intermediate order of creatures had once abounded, in which, as in the half-developed frog, the natures of both fish and reptile were united. But, though unacquainted with this strange analogy, the transformations were of themselves wonderful enough to fill for a time my whole mind. I remember being struck one afternoon, after spending my customary spare half hour beside the pond, and marking the peculiar style of colouring in the yellow and black libellulidæ in the common wasp, and in a yellow and black species of ichneumon fly, to detect in some half-dozen gentlemen's carriages that were standing opposite our work-shed--for the good old knight of Conon House had a dinner-party that evening--exactly the same style of ornamental colouring. The greater number of the vehicles were yellow and black--just as these were the prevailing colours among the wasps and libellulidæ; but there was a slight admixture of other colours among them too: there was at least one that was black and green, or black and blue, I forget which; and another black and brown. And so it was among the insects also: the same sort of taste, both in colour and the arrangements of colour, and even in the proportions of the various colours, seemed to have regulated the style of ornament manifested in the carriages of the dinner party, and of the insect visitors of the pond. Further, I thought I could detect a considerable degree of resemblance in form between a chariot and an insect. There was a great _abdominal_ body separated by a narrow isthmus from a _thoracic_ coach-box, where the directing power was stationed; while the wheels, poles, springs, and general framework on which the vehicle rested, corresponded to the wings, limbs, and antennæ of the insect. There was at least sufficient resemblance of form to justify resemblance of colour; and here _was_ the actual resemblance of colour which the resemblance of form justified.