The resemblance, which was perhaps at first only remote, is supposed to have been increased in the course of ages by the varieties being protected that more and more closely approached the species imitated, in form, colour, and movements. These resemblances are not only between insects of different genera and orders, but between insects and flowers, leaves, twigs, and bark of trees, and between insects and inanimate nature. They serve often for concealment, as when leaves are imitated by leaf-insects and many butterflies, or for a disguise that enables predatory species to get within reach of their prey, as in those spiders that resemble the petals of flowers amongst which they hide. (PLATE 1. ALLIGATORS IN SAN JUAN RIVER.) That I may not travel over the same ground twice, I may here mention that on a subsequent visit to Greytown I rode a few miles northward along the beach. On my return, I tied up the horse and walked about a mile over the sand-bank that extends down to the mouth of the river. A long, deep branch forms a favourite resort for alligators. At the far end of a sand-spit, near where some low trees grew, I saw several dark objects lying close to the water on the shelving banks. They were alligators basking in the sun. As I approached, most of them crawled into the water. Mr. Hollenbeck had been down a few days before shooting at them with a rifle, to try to get a skull of one of the monsters, and I passed a dead one that he had shot. As I walked up the beach, I saw many that were not less than fifteen feet in length. One lay motionless, and thinking it was another dead one, I was walking up to it, and had got within three yards, when I saw the film over its eye moving; otherwise it was quite still, and its teeth projecting beyond its lips added to its intense ugliness and appearance of death. There was no doubt, however, about the movement of the eye-covers, and I went back a short distance to look for a stick to throw at it; but when I turned again, the creature was just disappearing into the water. It is their habit to lie quite still, and catch animals that come near them. Whether or not it was waiting until I came within the swoop of its mighty tail I know not, but I had the feeling that I had escaped a great danger. It was curious that it should have been so bold only a few days after Mr. Hollenbeck had been down shooting at them. There were not less than twenty altogether, and they swam out into the middle of the inlet and floated about, looking like logs in the water, excepting that one stretched up its head and gave a bellow like a bull. They sometimes kill calves and young horses, and I was told of one that had seized a full-grown horse, but its struggles being observed, some natives ran down and saved it from being pulled into the water and drowned. I heard several stories of people being killed by them, but only one was well authenticated. This was told me by the head of the excellent Moravian Mission at