Packard.] 398 [February 26, 



the adult, referring the reader to the great work of Lacaze-Duthier^, 

 where the complicated structure of these parts is copiously illustrated 

 by drawings and descriptions. The learned entomologist, however, 

 only refers to the ovipositor, not describing the homologous parts in 

 the male; nor does he trace their development in the young. 



From the observations presented above it appears, that Lacaze- 

 Duthiers's conclusion, that the three elements (rhabdites) of the ovi- 

 positor grow from the ninth abdominal segment alone, is incorrect; the 

 first pair, according to our observations, arising from the eighth; tlie 

 oviduct, as he states, opening on the ninth urite. 



We have seen that these rhabdites, as Lacaze-Duthiers aptly terms 

 them, are developed irom the ahdominal sterna, and not from the pleural, 

 or Umb-bearlng, rey'ion of the body. So far as present observation goes 

 these rhabdites are never jointed. We should naturally endeavor to 

 find their homologues in the head of insects; but such homologues do 

 not seem to exist. The labrum and clypeus, and probably the lingua, 

 are sijigle parts, developed immediately upon the median line, the two 

 former being probably tergites, and not dividing into pairs; while the 

 rhabdites are double organs, and seem to be unicpie in their development 

 and function. They are morphologically pre-anal organs; while the 

 anal i<t//Iets, which are true jointed appendages, are post-anal append- 

 ages, being developed hehuul the anal opening. Regarding the insect 

 as consisting of two fore and hind halves, the two ends being, with 

 this view, I'cpetitions of each o her, 

 these anal stylets may be considered as 

 abdominal antenna\ so that the antennse 

 look one way, and their homologues, the 

 many-jointed antenniform anal stylet 

 (Fig. 1 1 . The antennii'orm anal stylet 

 of Mantis tessellata, after Lacaze-Duthiers), the opposite. 



These abdominal antennae, or feelers (being appendages of the 11th 

 abdouunal segment), must not be confounded with the ovipositor, as 

 in the highest insects, the H ymenoptera and Lepidopfera, they are, so 

 far as known to us, not present at all, though one distinguishing 

 mark of the former suborder is the sting, or when this is functionally 

 absent, the variously modified ovipositor. 



The presence of the anal stylet should be considered as a mark of 

 inferiority, as it is best developed in the lowest insects, the Orihojdera 

 and Neuroptera, and in the order of M(/7-iapo(ls. The researches of 

 Rathke and Claparede show that the three pairs of abdonnnal jointed 

 limbs which form the "spinnerets" in spiders, are developed, like the 

 cephalic and thoracic members, from the pleural or limb-bearing 

 region, and are homologous with the single pair of anal stylets of 

 insects, and the abdominal legs of Myriapoda. 



