GARDE X PESTS IN NEW ZEALAND 



middle finger of one hand to that of the other represent the number of 

 different kinds of living animals: then the last joint of the middle 

 finger of the right hand will be proportionate to the number of mammal? 

 (kangaroos, hoofed animals., rabbits, man, etc.), the second joint to the 

 reptiles and their relations, the first joint to the birds, and the distance 

 .be^yec'Q the -'kmickjes ;ar.d the wrist to the fishes. "In other words, you 

 ''c'ah' hold ' the so-called Zoological gardens and their aquarium annexes 

 in one hand." Finally, the distance between the wrist of the right arm 

 and the tip of the middle finger of the left will proportionately represent 

 all the known species of invertebrates, and of this section of the extended 

 arms all except between a wrist and an elbow will be insects. 



The zoologist classifies the animals under twelve main divisions, 

 of which eleven contain the invertebrates and one the vertebrates; these 

 divisions are arranged in a series, the first containing the simplest or 

 lower animals, and the last the most complex or highest. A glance at 

 this classification will serve to give some idea of the relative position 

 in the animal kingdom of the animals which will be dealt with in the 

 following pages. The very lowest forms, belonging to the first division, 

 are micro-organisms known as the Protozoa ; they inhabit water and soil, 

 and live upon their own kind or upon minute plants, including bacteria, 

 or are parasitic upon the higher animals, some of these parasites causing 

 such diseases as malaria. The Protozoa are single units of living matter 

 (protoplasm), and may be referred to as the one-celled animals; they 

 are mostly microscopic, and lead an independent life, or are associated 

 in colonies, but are capable, as a rule, of carrying on independently all 

 the functions of life, though there are no organs such as those of diges- 

 tion, respiration, and circulation, as we know them in the higher 

 animals. It is amongst such simple forms that the distinction between 

 the lowest animals and plants ceases to be clear. As will be discussed 

 later, there is evidence that certain Protozoa have an important influence 

 on soil fertility. 



The remaining eleven divisions contain all other animals, ranging 

 in size from mere specks to the mass of the elephant; the bodies of these 

 are built up of a complex aggregate of countless cells of protoplasm 

 arranged in groups to form the organs of digestion, circulation, respira- 

 tion, reproduction, etc., each having its definite function in the animals' 

 lives. The following ara some typical or well-known examples of each 

 of these division?, the technical names, with the exception of the 

 Protozoa, not being given: 



The Protozoa (reference should be made here to Fig. 1) are fol- 

 lowed by (2) sponges; (3) jelly-fish, sea-anemones, corals; (4) flat- 

 worms (tape- worms, etc.) ; (5) round worms (thread-worms, eel-worms) : 

 ((>) sea-mats, lamp-shells; (7) wheel-animalcules; (8) star-fish, sea- 

 urchins: (9) segmented worms (earthworms); (10) crayfish, woodlice. 

 centipedes, millipedes,, spiders, mites, insects; (11) shell-fish, slug?, 

 snails; (12) fish, frogs, lizards, birds, hedgehogs, rabbits, man. 



So far we have reviewed the animal kingdom from one aspect only 

 that of classification, based on the resemblances and differences of the 

 individuals. It is now necessary to look at the subject from the view- 

 point of the horticulturist that is, the relationships of the animals to 

 their surroundings, or environment, and to the welfare of man. Of the 



