CHAPTER IV 



ARRANGEMENT OF INTERNAL ORGANS MUSCLES NERVOUS SYSTEM 



GANGLIONIC CHAIN BRAIN SENSE-ORGANS ALIMENTARY 



CANAL MALPIGHIAN TUBES RESPIRATION TRACHEAL 



SYSTEM FUNCTION OF RESPIRATION BLOOD OR BLOOD- 

 CHYLE DORSAL VESSEL OR HEART FAT-BODY OVARIES 



TESTES PARTHENOGENESIS GLANDS. 



THE internal anatomy of Insects may be conveniently dealt with 

 under the following heads : (1) Muscular system ; (2) nervous 



FIG. 63. Diagram of arrangement of some of the internal organs of an Insect : a, mouth ; 

 b, mandible ; c, pharynx ; d, oesophagus ; e, salivary glands (usually extending 

 further backwards); /, eye; g, supra - oesophageal ganglion; h, bub-oesophageal 

 ganglion; i, tentorium ; j, aorta; & 1( k^, 3, entothorax ; l r l & , ventral nervous 

 chain ; m, .crop ; n, proveutriculus ; o, stomach ; p, Malpighian tubes ; q, small 

 intestine ; r, large intestine ; s, heart ; t, pericardial septum ; u, u, ovary composed 

 of four egg-tubes ; v, oviduct ; w, spermatheca (or an accessory gland) : x, retractile 

 ovipositor ; y, cercus ; z, labrum. 



system ; (3) alimentary system (under which may be included 

 secretion and excretion, about which in Insects very little is 

 known) ; (4) respiratory organs ; (5) circulatory system ; (6) fat- 

 body ; (7) reproductive system. 



