NO. 6 GRASSHOPPER ABDOMEN — SNODGRASS 7I 



It is thus rather curious to find that, while the external parts of 

 the male tetrigid abdomen (fig. 27 A) present the typical acridian 

 characters, the structure of the phallic organs should have so little 

 in common with these organs in the Acrididae. The male organs of 

 Tridactylidae, furthermore, are entirely different from those either 

 of the Tetrigidae or the Acrididae, which fact again is surprising 

 considering the close resemblance of the female ovipositor in all three 

 of these families. The lack of uniformity in the male organs, as 

 compared with the female organs, suggests that the common basic 

 structure of the phallus is something less fundamental than is that 

 of the ovipositor. 



COPULATION, AND INSEMINATION OF THE FEMALE 



Preliminary to copulation the male grasshopper places himself well 

 forward on the back of the female. With his fore legs he clasps the 

 pronotum of the female, the claws holding at the notch in the anterior 

 margin of the prothorax between the pronotum and the small exposed 

 part of the episternum ; the intermediate legs clasp the middle of 

 the female's body ; the hind legs are held in various positions and 

 take little part in the copulatory act. The male then lowers his ab- 

 domen along the side of the female's abdomen (in pictures almost 

 invariably on the left side, but Boldyrev says, sometimes on the left, 

 sometimes on the right). The genital lobe of the ninth segment of 

 the male is now depressed and the phallic organs protruded, the dorsal 

 lobe of the aedeagus being turned upward and forward. In order to 

 expose the spermathecal aperture of the female, which receives the end 

 of the male organ in copulation, the male, as described by Boldyrev 

 (1929) for Locusta migratoria, depresses the subgenital plate of the 

 female with the anterior hooks of the epiphallus. The penis is then 

 introduced into the genital chamber between and beneath the ventral 

 valves of the ovipositor and is inserted into the spermathecal canal. 

 In Locusta miffratoria, according to Boldyrev, the separation of the 

 lower valves of the ovipositor by the organ of the male stretches the 

 dorsal wall of the genital chamber and pulls back the folds that 

 ordinarily conceal the spermathecal opening ; the latter is now " opened 

 wide and the penis is plunged into it right up to its base." The penis, 

 or dorsal lobe of the aedeagus, in Locusta migratoria is long, slender, 

 and tapering (fig. 32 B); in forms in which the terminal part is 

 short and thick, as in Melanophis (figs. 37, 38, 40), it seems hardly 

 possible that the entire organ can be inserted ; probably in such cases 

 only the apical processes enter the spermathecal orifice. During copu- 

 lation the cerci of the male are said to grasp the base of the subgenital 



