166 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. XV. 



Chapter I. 



The Position of the Class Insecta in the Animal 



Kingdom. 



It will be at first necessary to consider shortly the position of the 

 Insecta in the Animal Kingdom, and with this object in view the 

 briefest of summaries of the Kingdom becomes essential. 



Animals are primarily divided into the two great groups of the 

 Protozoa or animals consisting of a single cell only (as, for instance, 

 the Amceba) and the Metazoa or multicellular animals. 



The latter are again sub-divided into the Ccelentera, or animals 

 without a body cavity (such as the sponge, coral, jellyfish) and 

 Coelomata, or animals provided with a body cavity. 



The Ccelomata comprise the rest of the Animal Kingdom and are 

 divided into seven great Phyla, consisting of the Platylielminthes 

 or Flat Worms ; Nemathehninthes or Round Worms ; Annelida or 

 Earth Worms, Sea Worms, and Leeches ; Arthropoda or Prawns, 

 Crabs, Spiders, Scorpions, Insects, Centipedes, Millipedes ; Echinoderma 

 comprising the Star Fish and Sea Urchins ; Mollusca or Snails, Slugs, 

 and Mussels ; and lastly the Vertebrata or Chordata, comprising the 

 Fishes, Frogs, Lizards, Birds and Mammals. 



We thus see that the Insecta form one of the divisions of the great 

 branch Arthropoda or segmented animals. They may be said to be 

 segmented animals, having three pairs of legs and breathing by trachece, 

 a system of air tubes ramifying through the body and opening on the 

 sides of the insect by means of a row of breathing holes or stigmata ; 

 the genital openings of insects are near the posterior end of the 

 body. 



We shall consider the Insecta as divided into the following nine 

 Orders : — Aptera (fish-insects) ; Orthoptera (cockroaches, mantis, locust, 

 grasshopper, cricket, &c.) ; Neuroptera (white-ants, lace-winged flies 

 ant lions, &c.) ; Hymenoptera (ichneumons, ants, bees, wasps, &c.) ; 

 Coleoptera (beetles) ; Lepidoptera (butterflies and moths) ; Diptera 

 (two-winged flies) ; Thysanoptera ; and Hemiptera (tree bugs, cicadas, 

 plant lice, and scale insects). 



Some General Notes on Insect Life.* 



It will be interesting to first glance briefly at some of the charac- 

 teristic features of Insect Life in general. Insects form by far the 



* To Dr. Sharp, F.R.S.,in the Cambridge Natural History, Vols. Vand VI, Insects, I am 

 indebted for some of the following interesting notea on the very varied features of Insect Life* 



