40 PHYSIOLOGICAL SERIES. 



innervates the reproductive organs in addition to the hinder 

 region of the body-wall. The connectives of the ventral 

 chain are very slender ; they lie close side by side, except 

 tatween the three thoracic ganglia where they are tra in- 

 versely separated. 0. C. 1299 G. 



D. 35. The larva of a Moth (Metura saundersii) contained within 

 its protective case and dissected from the ventral surface. 

 The nervous system is of extreme delicacy. It does not 

 differ in the number of its post-oral ganglia from that 

 shown in the preceding specimen, but the altered positions 

 of the ganglia relative to the body-segments and to one 

 another suggest that those changes have begun, which 

 finally, during the pupal stage, produce the longitudinal 

 concentration of the nervous system found in the imago. 

 The first abdominal ganglion is for example markedly 

 approximated to the metathoracic, and lies with it in the 

 metathoracic segment. 0. C. 1299 F. 



D. 36. Two specimens of the nervous system of the larva of a 

 Goat Moth (Cossus ligniperda) : one in situ seen from above. 

 the other isolated. The cerebral and suboesophageal ganglia 

 are moderately separate, but the prothoracic is alnut 

 confluent with the suboesophageal. It is followed l>v a 

 chain of 10 ganglia (2 thoracic and 8 abdominal). Between 

 the thoracic ganglia the connectives diverge laterally, 

 leaving an oval space. In the anterior of these spaces, in 

 the left specimen, a small median nerve can be seen, which 

 arises from the prothoracic ganglion and ends in two 

 lateral branches close in front of the mesothoracic. It 

 belongs to a series of median sympathetic nerves, found 

 commonly among insects ; as a rule each rises from one of 

 the two connectives close behind a ganglion, or from the 

 ganglion it-elf, runs to the -ucceeding ganglion and there 

 divides into two lateral branches, each of which joins one 

 of the peripheral nerves and is distributed to the respiratory 

 organ-. The abdominal ganglia are -ifuaied at equal 

 distance! apart, with the exception of the first which is 

 approximated to the metathoracic, and the last two which 

 are almost contiguous 



Catnr, Zeita. wiss. Zool., Bd. xxxv. 1881, p. 304. 



