420 MR. NEWPORT ON THE NERVOUS SYSTEM OF THE SPHINX LIGUSTRI. 



Fig. 6. Nervous system of the perfect insect Sphinx ligustri. 



A. Cerebral ganglia. 



B. Optic nerves. The figures refer to the number of the ganglia. 

 o, o, o. Respiratory nerves. 



p, />, p. Their division at the spiracles. 



Fig. 7. Lateral view of the cerebral and thoracic part of the nervous system in the 

 perfect state of the Sphinx, magnified two and a half diameters. 



Plate XIV. 



Fig. 8. The thoracic ganglia and nerves of Sphinx in the imago state. Figures as before. 



a. Nerve to the first pair of wings. 



b. The double-rooted origins of this nerve. 



c. A plexus or ganglion formed at the union of the two roots. 



d. The nerves to second pair of wings. 



e. Some separate filaments which are given to the muscles. 

 /.' Nerves to the second pair of legs. 



g, h. Tracheal vessels. 

 Fig. 9. The anterior portion of the abdominal nerves and columns, covered by the 

 investing structure {a), seen only in the perfect state of the insects. 

 h. Respiratory nerves. 



c. The moto-sensitive or symmetrical nerves. 

 Fig. 10. The cerebral ganglia and nerves of the proboscis, magnified fifteen diameters. 

 a. The great nerve to the proboscis. 

 h. Its entrance into the organ. 



c. The external branch. 



d. The main branch given to the muscles. 



e. The internal, or branch which runs along the grooved or internal side of 



the organ. 

 B. Optic nerve. 

 D. Antennal nerve. 

 Figg. II, 12, 13. Exhibit vertical sections of the larva, pupa, and imago states of 

 Sphinx ligustri, Linn. ; showing the relative situation of the circulatory, 

 alimentary, and nervous systems in the three stages, and also the dupli- 

 catures of the external integument as occasioned by the contractions and 

 re-attachments of the muscles at the period of changing from the larva to 

 the perfect state. The silk-vessels and part of the organs of generation, 

 &c. are omitted. The figures refer respectively to the number of the 

 segments. Magnified two and a half diameters. 

 «, h. The dorsal vessel with its appendages. 

 The alimentary canal, 

 c. The oesophagus. 



