XIl] 



ORDERS OF INSECTS 



255 



FIG. 106. FIG. 107. 



FIG. 106. View of male Cockchafer, Melolontha vulgaris, from which the dorsal 

 integument and heart have been removed to show the internal organs. 

 After Vogt and Yung. 



1. Cerebral ganglion. 2. 1st thoracic ganglion. 3. 2nd and 3rd 



thoracic ganglia fused. 4. Fused abdominal ganglia. 5. Oesophagus. 

 6. Mid-gut. 7. Small intestine. 8. Colon. 9. Rectum. 



10. Malpighian tubules, bro-wn portion with caeca. 11. Malpighian 



tubules, distal end. 12. Trachea with vesicles. 18. Testes, opening 

 into coiled vasa deferentia. 14. Penis. 15. Single vas deferens. 



FIG. 107. View of nervous system of the Cockchafer, Melolontha vulgaris. 



After Vogt and Yung. 



1. Cerebral ganglion. 2. Sub-oesophageal ganglion. 8. 1st thoracic 

 ganglion. 4. 2nd thoracic ganglion. 5. 3rd thoracic ganglion. 



6. Fused abdominal ganglia. 7. Nerves to antennae. 8. Optic 

 nerves. 9. Origin of sympathetic nerves. 10. Abdominal nerves, 

 a pair to each segment, which split into an anterior and posterior branch. 



Order X. Hymenoptera. 



The Hymenoptera (Gr. v^o'-Trrepo?, membrane-winged) have 

 mouth-parts adapted for biting and sucking. The ligula of the 

 labium is long and grooved, whilst the paraglossae are small. The 

 mandibles are well developed and the laciniae of the first maxillae 

 large. The four wings are alike, membranous in texture, but with 

 vastly fewer nervures than the wings of insects belonging to the 

 " Neuropterous " orders, and the hind wings are hooked on to the 

 anterior in such a way that the two wings of each side move 

 together. The metamorphosis is complete. 



