CLASS INSECTA. 

 CHAPTER I. 



ANATOMY OF INSECTS. 



Characteristics of the Arthropoda Insects Divisions of the Body Segments of the Abdomen Structure of the Thorax- 

 The Jointed Limbs Parts of the Leg The Feet The Wings The Head The Antenna; The Organs of the Mouth- 

 Segmentation of the Head Modifications of the Mouth in Sucking Insects -The "Moulting" The "Trans- 

 formations " of Insects : Larva, Pupa, and Winged Stages Internal Anatomy The Nervous System Structure 

 of the Eye -Function of the Antennae -The Digestive System The Circulatory Apparatus How Respiration 

 is Performed Reproduction Classification. 



THE Arthropoda,* as already stated in the Introduction to Invertebrate animals in general, are 

 characterised by having the integument of the body divided into a series of rings, generally hardened 



M.indil.lc 



Antenna 



Lubruin, ur Cppcr Lip 



Maxillary Palj>i 

 Labial Palpi 



. Elytron 



Wing 



Fig. 1. BEETLE (Calosoma sycophanta] WITH THE HEAD, THE PORTIONS OF THE THORAX, AND THB 



ABDOMEN SEPARATED AND MAGNIFIED. 



by deposition either of the horny substance, called chitine, of which the outer skin of these animals 

 fundamentally consists, or of carbonate of lime, and united by soft flexible portions of the skin, which 

 enable the parts to move more or less freely. These firm rings are called segments, or, by many 

 anatomists, somites, and also metameres, as being more or less repetitions of similar parts. So far the 

 Arthropoda agree with many Vermes, and in the older classifications the Arthropods and Verrnes 



* Greek, arthron, a joint ; pous, a foot. 

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