382 PHYSIOLOGY. 



canal, the former, however, beneath it, into the evacuating duct of the 

 sexual organs ; on the other side, by their similar form, they also 

 forming serpentine or ramose canals, which terminate in a larger 

 reservoir, or bladder. In both cases they are double, but the poison 

 organs empty themselves into a bladder with a single duct, whereas the 

 urinary bladders remain separated and have two distinct orifices. 



We also discover frequently in insects peculiar secretions, which are 

 found limited to certain families. They betray themselves especially 

 by the smell which insects possessing them either constantly produce, 

 or only upon certain occasions. Thus the large Carabodea smell like 

 fresh Russia leather, which must be ascribed to a secretion that is 

 emitted through one of the articulating membranes. This supposition 

 is supported by the milky secretion which is poured forth in abundance 

 through the articulating membrane between the head and prothorax 

 and mesothorax, by recently captured Dijfici, and which has an 

 offensive stench like that of putrid urine. In Meloe, a different 

 oily fluid is secreted in the articulating membranes of the legs. In 

 neither of the two former instances could I discover a distinct secreting 

 organ, and Brandt was equally unsuccessful in Meloe *. The sharp 

 secretion of the Cantharides is universally known, for which also no 

 distinct secreting organ is to be found, but which seems to be deposited 

 principally in the hard horny parts. Here the excretion exhibits 

 itself as a peculiar substance, which chemists designate by the name 

 of cantharis camphor t, and which alone possesses the property of 

 blistering. It is also found in other genera and species of this family, 

 for instance, in Mylabris, which is the true Cantharis of the ancients. 

 Other volatile, ethereal, and peculiar secretions are observed in 

 Callichroma moschatum, the spurious Spanish fly, which insect betrays 

 itself at a considerable distance even, by its agreeable and peculiar 

 smell ; in the stinking burying beetle (Necrophorus), dung beetles 

 (Scarabeufi^), and in some C/iri/somcke and Coccinellce. The last 

 especially, upon being touched, emit a yellow fluid through the segments 

 of the abdomen, which smells strongly of opium. Perhaps it is from 

 this that they have been applied in the toothach. The Hemiptera 

 are distinguished among the other orders, and especially the bugs, by a 

 very peculiar insufferable stench, which is, however, only to be detected 



* Arzneithiere, vol. ii. Pt. 4, p. 104. 



t Gmelin's Chemie, vol. ii. Pt. 1, p. 427. 



