As the beast approached the beach, lest the joke might be carried too far, we lent him a hand to dismount, while his steed crawled on as sedately as before into the water, and, as he swam off, turned round his head, as much as to say, "Hillo, master, are you not coming too?  Just try it, and see how you like a swim with me."  Mr Kilby told us that this animal had probably been sick, and had remained behind while his companions had taken to the sea, which they always do on the approach of summer.  In autumn they come on shore, and live in large herds in marshy places by the sides of rivers, eating grass like cattle.  The females, which are without the snout, suckle their young, of which they have generally two at a time.  As they are very slow in their movements, to afford themselves time to escape they have sentinels posted while they are feeding, whose duty is to give notice of approaching danger.  They are very good tempered and inoffensive, though the mothers will attack those who molest their young.  Mr Kilby told us of a man who had his leg bitten off by a female, while he was attempting to carry away her cub.  We now once more took to the boat.  We had not been long under weigh before I saw Mr Burkett looking up anxiously at the sky.