PHYS.—I fear I am not entomologist enough to follow the life of the May-fly, but I shall willingly have my attention directed to its habits. Indeed, I have often regretted that sportsmen were not fonder of zoology; they have so many opportunities, which other persons do not possess, of illustrating the origin and qualities of some of the most curious forms of animated nature; the causes and character of the migrations of animals; their relations to each other, and their place and order in the general scheme of the universe. It has always appeared to me, that the two great sources of change of place of animals, was the providing of food for themselves, and resting-places and food for their young. The great supposed migrations of herrings from the poles to the temperate zone have appeared to me to be only the approach of successive shoals from deep to shallow water, for the purpose of spawning. The migrations of salmon and trout are evidently for the purpose of depositing their ova, or of finding food after they have spawned. Swallows, and bee-eaters, decidedly pursue flies over half the globe; the scolopax or snipe tribe, in like manner, search for worms and larvæ,—flying from those countries where either frost or dryness prevents them from boring,—making generally small flights at a time, and resting on their travels where they find food. And a journey from England to Africa is no more for an animal that can fly, with the wind, one hundred miles in an hour, than a journey for a Londoner to his seat in a distant province. And the migrations of smaller fishes or birds always occasion the migration of larger ones, that prey on them. Thus, the seal follows the salmon, in summer, to the mouths of rivers; the hake follows the herring and pilchard; hawks are seen in great quantities, in the month of May, coming into the east of Europe, after quails and land-rails; and locusts are followed by numerous birds, that, fortunately for the agriculturist, make them their prey. HAL.—It is not possible to follow the amusement of angling, without having your attention often directed to the modes of life of fishes, insects, and birds, and many curious and interesting facts, as it were, forced upon your observation. I consider you (_Physicus_), as pledged to make one of our fishing party; and I hope, in a few days, to give you an invitation to meet a few worthy friends on the banks of the Colne. And you (_Poietes_), who, I know, are an initiated disciple of Walton’s school, will, I trust, join us. We will endeavour to secure a fine day; two hours, in a light carriage with good horses, will carry us to our ground; and I think I can promise you green meadows, shady trees, the song of the nightingale, and a full and clear river.