58 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 68 



lies on either side of the abdominal cavity. Each half is divided into 

 the three following parts : ( i ) The spherical reservoir lies under 

 the last dorsal segment of the abdomen just under the rectum and 

 opens at the side of the anus ; (2) the preparator is a large saclike 

 organ lying just behind the reservoir; and (3) the long threadlike 

 duct is the anterior continuation of the preparator. 



He found an organ similar to the preparator in several other 

 carabids and also in Blaps. These beetles, when excited, discharge 

 an acrid and caustic liquid through the two apertures near the anus. 

 Dufour (1826) remarks that the Dytiscidse are able to discharge a 

 colorless and disagreeable fluid from the anus. Silphidse emit from 

 both the mouth and vent a fetid liquid having an ammoniacal odor ; 

 the members of this family have a single anal gland. 



Meckel (1846) says that the reservoir of the anal gland in Dytiscns 

 contains a yellowish-white emulsion. The secretion has a rancid 

 odor, an acid reaction, and a defensive function. The gland cells are 

 comparatively large, and in the collecting tubes leading from these 

 cells may be seen drops of the secretion. In Carabus auratus, C. 

 coucellatns, and ChlcEnius vestitus the gland consists of grapelike 

 bunches ; in Chlamius velutionus of three short, broad sacs which 

 empty into a canal (the efiferent canal) leading to the exterior; in 

 Aptinus the gland is five lobed ; in Brachinus it consists of convolu- 

 tions of blind sacs which unite at a common point with the efferent 

 canal ; in Bombylius and the water beetles the gland is a long, con- 

 voluted, and closed vessel. 



Karsten (1848) remarks that this organ in Brachinus complanatus 

 is paired. Either external opening lies above and to one side of the 

 anus, and the posterior end of either kidney-shaped reservoir com- 

 municates with its respective external opening. From the anterior 

 end of the reservoir runs a collecting tube which soon divided into 

 twelve glandular tubes, each one of which has a central canal, and 

 its peripheral end is free. The gland cells are spindle-shaped and 

 stand perpendicularly to the central canal, which is filled with a 

 greenish fluid. 



Candeze (1874) reports that certain carabid beetles throw a burn- 

 ing and extremely fetid liquid on their enemies. 



Gissler (1879) remarks that the repugnatorial gland of Eleodes 

 gigantea and E. dentipes is paired. The secretion has an intensely 

 penetrating odor and causes the eyes to shed tears. When irritated, 

 these beetles stand on their first two pairs of legs with the abdomen 

 high in the air and -the liquid is thrown right and left. 



