330 



N. E. McINDOO 



Fig. 22 Semidiagrammatic drawing from a single section of the same imago 

 worker as in figures 20 and 21. This represents the complete innervation of the 

 base of the front wing. The hard chitin {Ch) of the wing is shaded with small 

 broken lines, the articular chitin (Ai'tCh) with dots, arid the hard chitin of the 

 thorax (ChTh) with heavy broken lines. X 78. 



Fig. 23 Olfactory pores and sense cells (SC) seen in cross sections of the sting 

 of a 19-day-old worker pupa. A, pore and its sense fiber {SF) from shaft at 

 e, X 700. B, pore and sense cell from shaft midway between c and e (fig. 14 

 A), X 700. C, cross section through the shaft (Sh) and lancets (Let) of a sting, 

 showing the olfactory pores and their sense cells, X 350. In C, the pores, sense 

 cells, and hypodermis are drawn diagrammatically. The remaining parts of C 

 and all of A and B were drawn with aid of a camera lucida. 



chitinous layers, whether nearly or completely developed, except 

 where they are associated with the sense cells. 



The large, nerve of the leg is also easily traced to the thorax. 

 By using several of the sections from the thorax of an adult worker 

 these nerves were followed to large ganglia in the thorax. Ac- 

 cording to Snodgrass ('10) the prothoracic ganglion innervates 

 the prothorax and the first pair of legs. The second thoracic 



