Siructnriil ('liarackrl.'<llcs of I'ronii/xi. 85 



of tlic Mian V tliousaudsof butterflies and moths* The other organ 

 is the ovipositor, which, instead of being a simple opening, as 

 tvpically found in Lepidoptera. is here modified into a complex 

 (•oin1)ination of lance and saw. Ordinarily it is withdrawn and 

 hidden, but when in action is projected far beyond the tip of 

 the abdomen and is then seen to consist of two principal parts 

 the basal part being imbricato-granulate — /. c. having a delicate 

 file-like structure, the terminal part being smooth, but having 

 ni^ar tlie end a dorsal serrate chitinous wing and a still more 

 strongly toothed corneous tip. The internal structure is seen to 

 consist of two stout rods, extending along the thin walls to the 

 very tip, and of a ventral canal or passage-way for the delicate 

 t)viduct, which is silk-like and elastic and may be extruded for 

 a great length from an outlet near the end of the ovipositor. 

 This oviduct is smooth basally, but armed along its terminal 

 third with retrorse hairs, increasing somewhat in number and 

 strength toward the tip, around which they are almost spinous. 

 At first sight these would seem to be out of place and to impede 

 rather than aid the insertion of such a delicate filament ; but, 

 as we shall })resently see, the act of oviposition is a most intri- 

 cate and difficult one and these hairs are doubtless sensitive and 

 tactile and serve the double purpose of enabling the moth to feel 

 her way in the ovarian cell and of temporarily anchoring in the 

 soft wall thereof while the egg is being passed to its destination. 

 It will be seen that this ovipositor is admiraidy adapted for cleav- 

 ing through the young fruit and then running the egg into the 

 ovarian cavity, as will be presently described. The manner in 

 which this ovipositor is worked by the four rods attached to 

 strong muscles is indicated at Fig. 1, C, the two inner rods form- 

 ing, as already indicated, the rigid i)ortion of the ovipositor 

 proi)er and the imbricate basal portion of the covering facilitat- 

 ing the invagination of the basal part when the ovipositor is 

 withdrawn. The two outer rods are attached to strong muscu- 

 lar tissue in the walls of the vagina, and when the ovipositor is 

 extended to its utmost limit this vaginal portion is partially ex- 

 truded so as to appear like a l)asal subjoint. More detailed 

 characterization of these parts is unnecessary in this connection. 



* There are over 12,000 described species of Lepidoptera from Europe 

 and America, and those from other parts of the world will doul>le this 

 number. Nearly as many more remain, perhaps, to be described. 



