318 



The Large Poplar Longhorn 



present on its ventral wall three chitinous rods (r). Each rod is somewhat 

 broadened at the end of the sac next the membranous tube and is 

 pointed at the other end. 



On the ventral surface of that portion of the sac between the first and 

 second bend, there is placed a sheet of thin chitin (cp), which, under the 

 high power of the microscope, shows a radula-like surface (see Fig. 16 b). 



Fig. 16 a. Side view of internal sac and the median lobe; the latter is cut open to show 



course of the former; the tegmen is here removed (highly magnified). 

 Fig. 16 6. Portion of the internal sac bearing the armature is shown here straightened out 



(highly magnified). 



cp = chitinous plate; D = dorsal side of median lobe; e/ = common or ejaculatory duct; 



ml = median lobe; mo = median orifice; r = rods; 5= first pair of chitinous rods; 



st = membranous tube; <=second pair of chitinous rods; F= ventral side of median 



lobe. 



Just as the internal sac enters the median lobe there are present 

 two pairs of short, stout chitinous rods. 



The first pair (s) is placed on the lateral surfaces of the sac and arch 

 over from the dorsal to the ventral surfaces (see Fig. 16, s). 



