MR. NEWPORT ON THE NERVOUS SYSTEM OF THE SPHINX LIGUSTRI. 409 



to each ganglion, and is given to the internal series of muscles. A narrow slip or riband 

 [figg. 44. and 45. (c)], about one third the diameter of each cord, extends along the 

 median line above the cords from one end of the body to the other, as in the Scorpion. 

 This, like the tract in the Scorpion, has been thought to be the motor tract, but is, I 

 think, analogous to the transverse or involuntary nerves of insects. In passing over 

 each ganglion this tract is connected with the nerves by four pairs of very minute 

 filaments. It is interesting to remark the existence of distinct ganglia, from which 

 the antennal nerves originate, situated upon and forming portions of the cerebral 

 ganglia [fig. 48. (d)], just the same as the ganglia upon the antennal feelers in the 

 Lobster [fig. 40. {h, c, d)'] ; and also to compare the size of the antennal nerves in Sco- 

 lopendra with the optic nerves in the same animal, which are now gaining much im- 

 portance in the animal series, and begin to share the cerebral ganglia nearly equally 

 with the cerebral prolongations of the cords — the antennae. In the Scolopendra we 

 have thus a clear proof that the anterior or cerebral portion of the nervous system is 

 formed originally by the coalescence of at least two pairs of ganglia, the antennal and 

 optic ganglia, just the same as the caudal ganglion is formed by the ganglia of the 

 penultimate united with the ganglion of the terminal segment of the body. The 

 motor root of the great mandibular nerve is very distinct from the sensitive [e] . 



Although a double nervous column was thus proved to exist in Crustacea, Arachnida, 

 and Myriapodtty it was not until lately that I have been able to identify and to distin- 

 guish the motor and sensitive columns from each other in insects. Their actual ex- 

 istence, therefore, could only be inferred from the discovery of them in other Articii- 

 lata. It has been shown in another part of this paper, that the transverse series of 

 nerves in insects cannot be analogous to the true motor nerves, from their having 

 ganglia upon them in several genera. It was in the Carabus, Linn., the very insect in 

 which the ganglia of the transverse nerves are most distinct [fig. 38. (c)], that I first 

 identified the double structure of the cords in insects, and clearly distinguished the 

 motor from the sensitive column {a, b). The motor roots are given off*, and unite with 

 the sensitive from the ganglia to form the symmetrical nerves, exactly the same as in 

 the Lobster. The motor, sensitive, and transverse or involuntary nerves are all very 

 distinct in the Green Grasshopper, Gryllus viridksimus, Linn. [Plate XVI. fig. 39. 

 (a, h, c)]. Indeed they are so distinct under the microscope as to have been readily 

 seen by a friend who was with me when examining the specimen. But it is in Lepido- 

 pterous insects, Papilio, Phalcena, and Sphinx, that the detection of the three kinds 

 of nerves, motor, sensitive, and transverse or involuntary, has given me most satisfac- 

 tion ; because it is in these genera that the transverse nerves, from their large size 

 and from the apparent absence of any other motor column, have been believed to be 

 analogous to the motor nerves of verteb rated animals. 



In the larva of the Sphinw Hgustri, soon after it has entered its last skin, the three 

 kinds of nerves are more distinct than at a subsequent period. The two sensitive 

 columns, or gangliated portions of the cords, lie close to the under surface of the 



