In regard to the animals we are to deal with in this book we hardly need to use technical names, and will do so as sparingly as possible.
The first and highest group in the animal kingdom are the Mammalia. These are vertebrate (or back-boned) animals which are fur-clad, and the females have glands which secrete milk for the nourishment of the young. These glands open to the surface of the body by teats, or mammae, hence the name. Mammals are all warm-blooded animals. There are many other distinctive features by which animals of this group are characterized, both anatomical and physiological, but here we intend to give only the most distinctive points.
Mammals are divided into several orders, and of these six are now represented in the New Zealand fauna. As I do not wish to burden these pages with technicalities, I shall give only the briefest accounts of these orders, and mention the animals found here which belong to them.
1. The animals of the order Marsupialia are popularly known as pouched animals. Their most distinctive character is that the mammae lie within a pouch in which the young are placed while in an imperfect condition. Two kinds of animals belonging to this order are wild in New Zealand—namely, wallabies and so-called opossums.
2. The order Ungulata includes a large assemblage of herbivorous animals of somewhat diverse character. They possess theoretically five toes in each foot, but actually these are reduced to two, or, in the case of the horse, to one toe. This reduction is accompanied by a reduced condition of the ulna, which is fused with the radius, and the fibula is fused with the tibia. The order includes horses, pigs, deer, oxen, sheep, and goats, all of which are, or have been, wild in this country.
3. The third order, Cetacea, forms an extraordinary group of warm-blooded animals, which breathe air and suckle their young, but live in the sea. It includes all the forms known as whales, and all are indigenous to New Zealand.
4. The Carnivora are, as their name implies, flesh-eaters. Their teeth have sharp cutting-edges, and the canines are well developed to enable them to tear the flesh off their prey. The order includes cats, dogs, stoats, ferrets, and weasels, all of which have been introduced; and seals, which are indigenous.
5. The animals of the order Rodentia are only occasionally carnivorous. All possess long incisors furnished with strong chisel-like edges, and with these they are able to gnaw their food, from which circumstance the name is derived. The canine teeth are quite absent. In New Zealand are to be found rats, mice, rabbits, and hares.
6. The last order represented here is the Insectivora, a group, mostly of small animals, which is very difficult to define. The only animal belonging to the order in New Zealand is the hedgehog.