1916] Breeding Habits of the Orthoptera 129 



less regular sequence ; first, the non-development of an external 

 ovipositor; second, an ovipositor developed but nonfunctional; 

 third, a comparatively unspecialized ovipositor and lastly, a 

 highly specialized and functional ovipositor. 



The classification in Figure 3 is based upon the presence of a 

 definite egg-capsule or the approach to it in those forms which 

 do not possess it. As in Figure 2 the Mantids and Blattids 

 stand apart from the other forms being divided from the other 

 forms because of their possession of an egg capsule or ootheca. 

 The Locustidas and the Gryllidae again occur at the other 

 extreme, because they lay their eggs singly or in masses of only 

 two or three. Again the Acrididce occupy an intermediate posi- 

 tion because they resemble the Blattidas and the Mantidas in 



GRYLLIDAE 



LOCUST^DAEfACRIDIDAE MANTIDAE 



BLATTIDAE 



PHASMIDAE 



Fig. 3. Classification based upon the occurrence of an egg capsule. Mantidae 

 and Blattidae having a definite ootheca are placed by themselves. Gryllidae 

 and Locustidse laying eggs singly are placed at the opposite extreme. Acrididag, 

 laying eggs in compact mass are placed between. Phasmidse are placed near 

 Acrididas because eggs are all discharged at once. Since they have no approach 

 to an ootheca they are inclined to the left extreme. 



laying their eggs all at once but in not having a definite egg 

 capsule. The position of the Phasmids in this classification is 

 doubtful. The fact that they choose no special place for depos- 

 iting their eggs and that they deposit them in a very loose 

 manner, indicates a rather low degree of specialization. They 

 have been placed near the Locustidas and the Gryllidae because 

 they resemble these families in depositing their eggs singly. 



In Figure 4 three factors are considered in the classification 

 of one of the stems established in Figures 2 and 3. These 

 factors are the presence or the absence of a spermatophore, the 

 relative position of the bodies during copulation and the dura- 

 tion of copulation. The three factors are intimately associated. 



