FCETID GLANDS OF ORTHOPTERA 371 



chin). Haase states that these glands become everted by blood- 

 pressure and give out the well-known disagreeable smell of these 

 insects. He states that in the male of P. germanica the dorsal glands 

 in the 6th and 7th abdominal segments are without hairs and produce 

 an oily secretion; they function as odoriferous organs in sexual 

 union. 



In the male of another Blattid (Aphlebia bimttata) of the Canary 

 Islands, Krauss has detected two yellowish dorsal sacs 1.5 mm. in 

 length, opening out on the 7th abdominal segment, and filled full of 

 long yellowish hairs, the ends directed towards the opening, where 

 they form a thick tuft. These eversible glands lined with hairs 

 appear to be closely similar to the long slender eversible hairy 

 appendages or scent organs of certain Arctian and Syntomid moths. 

 (Fig. 359.) 



We have found the external median wart with lateral lids or flaps 

 in between the 5th and 6th tergites of Platyzosteria ingens Scudder, 

 a large wingless Blattid living under the leaf 

 scars of the cocoanut tree in Southern Florida 

 (Fig. 360), but were unable to detect them in 

 Polyzosteria or in the common Blabera of Cuba, 

 or in another genus from Cordova, Mexico. 



In another group of Orthoptera, the Phas- 

 midse, occur a pair of dorsal prothoracic glands, 

 each opening by a pore and present in both 

 sexes. In the walking-stick, Anisomorpha buprestoides, $ and ? , 

 these openings are situated on each side of the prothorax at its 

 upper anterior extremity, situated at the bottom of a large deep pit. 

 When seized it discharged a " milky white fluid from the pores 

 of the thorax, diffusing a strong odor, in a great measure like that 

 of the common Gnaphalium or life everlasting" (Peale in Say's 

 American Entomology, i. p. 84). Boll states that the females when 

 captured " spurt from the prothorax, somewhat after the manner of 

 bombardier beetles, a strong vapor, which slightly burnt the skin; 

 when the females were seized by the males a thick fluid oozed from 

 the same spot." Scudder describes these glands in another Phasmid 

 (Autolyca pallidicornis) as two straight, flattened, ribbon-like bodies, 

 with thick walls, broadly rounded at the end, lying side by side and 

 extending to the hinder end of the mesothorax. In Anisomorpha 

 buprestoides the glands are of the same size and shape (Scudder). 

 In Diapheromera femorata the repugnatorial foramina are very 

 minute, and the apparatus within consists of a pair of small obovate 

 or subfusiform sacs, one on each side of the prothorax, about 1 mm. 



