26 BULLETIN OK WISCONSIN NATURAL HISTOEY SOCIETY. VOL. 4, NOS. 1-2. 



The carrion beetles of the family Silphidse emit from the mouth 

 and anus a fetid liquid with an ammoniacal odor ( Packard '98 p. 

 375) as we have frequently noticed. This is probably derived 

 from the decomposition of its food and is not a glandular product 

 at all. 



SPECIAL PART. 



Experiments ivith Myriapods. 



For many years the repugnatorial secretion of the Julidse has 

 been referred to by various writers, although even yet nothing 

 definite is known of its chemical composition. As long ago .is 

 1870 Prof. E. D. Cope ('70) remarked that "the species of Spiro- 

 bolus and Julns discharge a yellowish juice having much the smell 

 of aqua regia and a very acrid taste. The Spirostrephon lactarius 

 exudes from a series of lateral pores a fluid which has in its odor 

 a close resemblance to creasote." Wheeler ('90) has "frequently 

 seen our common Julus,* when irritated, emit from its repugna- 

 tory glands a brown liquid with a pungent odor not unlike bro- 

 mine." More recently Cook ('cx)) has treated in greater detail the 

 question of this secretion. 



We quote the following from his observations : "When the 

 liquid comes in contact with the skin a yellowish green stain 

 results, which gradually deepens to a dull purple. * * * The 

 alcohol in which these large diplopods are collected takes on 

 similar colors, yellowish green at first, changing to a very deep 

 purplish red, and has a characteristic disagreeable odor different 

 from that of the living animal, but still in some respects suggest- 

 ing it. This odor Loew considered similar to that of pyridine. 

 * * * Direct exposure to the light and heat of the sun is also 

 speedily fatal to many diplopoda, the heavily armored Spiroboli 

 are often quite dead after ten or fifteen minutes' exposure. That 

 this susceptibility may prove to be the result of some chemical 

 change or dissociation of the stored repugnatorial fluid is appar- 

 ently indicated by the fact that animals killed by exposure to the 

 sun do not stain the alcohol as described above, the repugnatorial 

 fluid having oozed out and having been evaporated from the sur- 

 face of the segments. This suggests a further possibility that 

 the material elaborated in the repugnatorial glands may not attain 

 its final and effective composition until directly or indirectly acted 

 upon by the air." 



* Probablj^ identical with the species of Spiroiolus here considered. 



