FIFTH ANNUAL REPORT 



THE ANEMAL KINGDOM. 



Animals are variously classified by zoologists, but the best known 

 and most comprehensive system of classification is that called the 

 Cuvierian, which separates them into four great Branches or Subking- 

 doms. These are again divided into Classes, Orders, Families, Genera, 

 Species and Varieties, each division being frequently subdivided into 

 minor groups. The four Subkingdoms are : 



1 — Vertebrata or Backbone Animals, comprising the four respect- 

 ive classes of Mammalia (mammals), Aves (birds), Eeptilia (rep- 

 tiles), and Pisces (fishes). Normally these all have four limbs, and 

 an internal skeleton to which the muscles are attached. 



2 — Articulata or Jointed or Segmented Animals, comprising the 

 five classes of Insecta (insects), AraoJinida (spiders, mites, etc.), 

 Crustacea (crabs, lobsters, etc.), Myriapoda (thousand-legged worms), 

 and Annelida^' (true worms, as leech, earthworm, etc.). 



These animals are readily distinguished by their jointed or seg- 

 mented nature. It is plainly seen in a caterpillar as it crWls along ; 

 each joint moves one after the other, with its own peculiar motion; 

 each has its separate set of organs, so that a caterpillar may be said to 

 have a head and 12 distinct bodies attached, for which reason it has 

 4,000 muscles to move its body, while man has only 529. The jointed 

 character is seen even in the Earthworm and in the Leech, but not in 

 the slug, which is a Molluscous — not an Articulate animal. Articu- 

 lates are further characterized by having no internal skeleton ; they 

 wear their skeleton on the outside, and every one must have noticed 

 the close resemblance which the exterior of the limbs of a grasshop- 

 per or of a lobster bears to the bones of our own limbs or to those of 

 other Vertebrates. * Sidney Smith wished that, in hot weather, he 

 could put off his flesh and sit in his bones. He ought to have been 

 an Articulate 1 It is true that some Articulates, and almost all insects 

 in their young and larval days, have this outer skeleton quite soft and 

 delicate; but the same may be said of the internal skeleton of Ver- 

 tebrates. We may crush and crunch with ease the bones of a newly 

 hatched chick; but he who would undertake to do likewise by those 

 of an old rooster, would, I fancy, have a rather tough job of it! 



3 — MoLLUscA or Soft-bodied Animals. These are without distinct 

 joints, and have neither internal nor external skeleton, the surface 

 being soft, flexible and retractile, and often covered with calcareous 

 deposits which assume a variety of different forms. 



*Eolleston (Forms of Animal Life — a work propounding a more modern system of classification, 

 which, though less simple than the Cuvierian, every zoologist should study) ,' makes of the Articulata 

 two suhkingdoms : 1st, Arthropoda (rj.pf^po\/, joint; —odoq. foot), including the tracheate Insecta, 

 Myriapoda and Arachnida and the branchiate Crustacea; 2nd, Vbbmes, including five Classes — thus 

 separating the articulates without legs from those which have legs. 



