Moreover, most herbivorous animals have a slow system of digestion, even in a domestic state; as, for instance, our cattle and sheep. This appears to be more conspicuously the case in the musk-ox, the reindeer, and the Arctic hare, and is of great utility in lands where vegetation is scanty and wide-spread, and the weather occasionally so severe as to compel these creatures, for two or three days at a time, to think only of their safety by seeking shelter from the snow-storms in deep ravines or under lofty cliffs. It appears in their case as if Nature extracted from their food a greater quantity of nourishment than she does from that of animals in more southern latitudes; or possibly, the food, by the mere act of remaining in the stomach or intestines, serves to check the cravings of appetite, though no further nutriment should be extracted. Most of the musk-oxen and deer shot in Captain M’Clintock’s expedition, and especially the musk-oxen, had their entrails distended with food apparently quite digested, while the surrounding country in many cases was absolutely barren and lifeless,--inducing the conclusion that these creatures had been a long time collecting their supplies, as also that it had been a long time swallowed, and necessitated the full activity of the vital principle to prevent the food from proving a source of disease. This, indeed, was clearly proved in the case of the musk-oxen, which, if shot, and left twelve hours without being disembowelled, grew tainted throughout with a strong musky odour, rendering the flesh uneatable. It may also be stated, as an illustration of the facility with which the reindeer can winter in high latitudes, that in Lapland, where they are used as beasts of draught, a daily supply of four pounds of lichen (_Cenomyce rangiferina_) is considered ample for a working animal; and on this dietary a reindeer will be in sufficiently good condition to go without food occasionally for two or three days, and yet, to all appearance, not to be distressed. Thus, as regards its stores of food, and its provision against the severity of the Arctic winter, the reindeer would seem to be suitably and amply endowed; and its greatest trial is the incessant rapacity of the wolves that follow its track throughout the winter season. As that season advances, the unfortunate animal apparently resigns itself to an evil which it cannot avoid or avert; and the calm composure with which a small troop of these creatures will graze with an _entourage_ of half a dozen wolves is not less curious to the observer than philosophical on the part of the reindeer!