42 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 68 



two glands is a straight, ribbonlike blind sac with stout walls. It 

 extends from the posterior extremity of the mesothorax where it is 

 broadly rounded to the anterior part of the prothorax where it is 

 cylindrical. Here the secretion comes to the exterior through the 

 slitlike aperture. 



Haase (1889b) considers the preceding means of defense as an 

 argument against the doctrine of Wallace and Poulton. According to 

 this doctrine the non-edible species are not eaten, presumably because 

 they have a glaring defensive color. Walking-sticks do not have 

 such an appearance and yet are not eaten, for they defend themselves 

 by use of stink glands. 



Maynard (1889) also asserts that both sexes of Anisomorpha 

 huprestoides, when irritated, are able to squirt two streams of a 

 vaporous fluid 6 inches from the prothorax. When expelled the 

 liquid is milky but almost instantly it changes to a vapor and has 

 a pungent or peppery odor. 



(b) GLANDS IN METATHORAX OF CERTAIN HEMIPTERA 



Leidy (1847) describes the odoriferous glands of the electric 

 light bug, Belostoma, as follows : 



These consist of two moderately long copcal tubes situated within the 

 metathorax, beneath the other viscera, and extending into the anterior part 

 of the abdomen. They are convoluted together in such a manner, that after 

 one or two turns the closed extremity is brought close to the termination, 

 both of which extremities are concealed by the passage over them of the 

 ventral cord. They open externally between the coxse of the posterior legs. 



Leidy (1849) describes the odoriferous glands of Hemiptera as 

 follows : 



In Hemipterous insects these bodies are situated within the posterior part 

 of the metathorax or anterior part of the abdomen, and consist of one or two, 

 more or less long and convoluted cceca, which open exteriorly, usually between 

 the coxae of the middle and posterior legs. 



Kiinckel (1866) asserts that the scent-producing organ of Penta- 

 tomidcB consists of a sac in the ventro-anterior portion of the abdo- 

 men. The sac opens to the exterior through two ostioles in the 

 metathorax near the base of the hind pair of legs. The same author 

 (1895) says that the Cimicidse, Pentatomidse, Coreidas, and Lygaeidae 

 are provided with two systems of scent-producing organs. The larvae 

 and nymphs have a tergo-abdominal system and the adults have a 

 sternal metathoracic system like the one described above. Kiinckel 

 (1886) claims that the repugnant odor of young bed bugs. Cimex 



