NERVOUS SYSTEM OF GRASSHOPPER — SCHMITT 317 



Maki (1936) describes four pairs of lateral nerve roots extending 

 from the mesothoracic ganglion in a neuropteron, Chaiiliodes. A 

 tabulation of the muscles innervated by the second and the third of 

 these roots, as described by Maki, indicates a nerve-muscle arrange- 

 ment similar to that in Dissosteira. Table 3 lists the muscles, as named 

 and numbered by Maki, which he described as innervated by the second 

 root ; and table 4 supplies the same data regarding muscles innervated 

 by the third root. 



Unfortunately, Maki's figures and text do not indicate the inner- 

 vation of the anterior sternal promotor of the coxa (his 131), but 

 apart from that, it may be seen that in Chauliodes, as in Dissosteira, 

 two primary innervation patterns exist, one supplying nerves to an 



Table 4. — Mesothoracic muscles of Chauliodes innervated by the third 



nerve root 



(Data from Maki, 1936) 



Maki number Name of muscle 



118 5th tergopleural 



1 19a Pleuroaxillary 



119b Pleuroaxillary 



120 Epimero-subalar 



125 Dorsal furco-entopleural 



126 Ventral furco-entopleural 



128 1st tergal remotor 



129 2d tergal remotor 



130 3d tergal remotor 



136 Coxa-subalar 



anterior segmental group of muscles, and the second supplying nerves 

 to an essentially posterior group of muscles. 



IV. THE INNERVATION OF THE MESOTHORACIC LEG 



The innervation of the muscles of the mesothoracic leg of Dis- 

 sosteira is provided by the largest branch of the third root. A very 

 fine short branch, just within the trochanter, innervates the rednctor 

 of the femur (104). The main leg nerve provides two fine branches 

 within the trochanter, both entering the proximal fibers of the depres- 

 sor of the tibia (107). Near its entrance into the femur, the main 

 nerve bifurcates, a branch passing on either side of the depressor of 

 the tibia. Branches of these nerves enter the anterior levator of the 

 tibia (105) and the posterior levator of the tibia (106). Both of the 

 nerves formed by the bifurcation of the main nerve enter the tibia 

 and provide innervation to the retractor of the claws (no). The 



