524 CAROLINE BURLING THOMPSON 



wing pads shows the same conditions as in the young wingless 

 soldier nymphs. My conclusion is, therefore, that the male 

 soldier of T. angiisticolhs, as well as the female soldier, is actually 

 sterile, although near the ancestral state of fertihty. 



Current literature affords other instances of sterility, although 

 spermatozoa are formed by the testis. 



Boring and Pearl ('18), in a study of hermaphrodite birds, 

 have noted a case of sperm in the testis without correlated sex 

 behavior. In reference to the bird known as 1426, they say: 

 ''This is the most interesting of the Holland birds, absolutely 

 indifferent as to its sex behavior and yet with sperm in the testis, 

 and at least one corpus luteum remnant in the ovary, and the 

 ovary of a laying hen." 



Safir ('20), referring to the cause of sterihty in the XO males of 

 Drosophila, states that the XO males do not inject sperm into 

 the female during copulation, but that when the XO males were 

 dissected the testes appeared perfectly normal in shape and color, 

 though of smaller size. When the testes were teased open the 

 bundles of sperm remained compact, and when separated artifi- 

 cially it was found that the sperm was non-motile. After many 

 dissections ''it became apparent that the immediate cause of the 

 sterility was the non-motihty of the relatively scanty sperm." 

 Safir also notes that the cell bodies of the primary and secondary 

 spermatocytes of Drosophila often fail to divide after the nuclear 

 divisions, forming giant multinuclear cells, the spermatids, which, 

 he beheves, often die and disintegrate without the formation of 

 spermatozoa, but, in other cases, develop into the bundles of non- 

 motile spermatozoa. The resemblance of this spermatogenesis 

 to that of Termopsis, as described by Stevens ('05), gives rise 

 to interesting speculations. 



The fat-body of the abdomen of soldier nymphs, though copi- 

 ous, is far less developed than in the nymphs of the first and 

 second reproductive forms. In the adult soldiers the fat-body is 

 reduced to a thin layer beneath the skin. 



