104 THE CANADIAN ENTOMOLOGIST. 



invalid, and that, consequently, King Edward VII. is not the King of 

 England !" 



Mr. Verrall is to be congratulated on the completion of the second 

 volume of the magnificent series planned by him. Such work is not of 

 merely local or even national value, but affects entomology throughout 

 the world. It sets a higher standard for us all. 



J. M. Aldrich, Moscow, Ida. 



SECRETION OF HYDROCYANIC ACID BY LEPTODESMUS 



HAYDENIANUS, WOOD. 



A number of instances of secretions of free hydrocyanic acid in the 

 Myriapods of the family Polydcsmidie have been recorded, and it is quite 

 probable that this power is possessed by all the members of the family. 

 In 1882 Egeling* discovered that Paradesmus gracilis, Koch. f secreted 

 besides benzaldehyde free hydrocyanic acid. Weber (Archiv. f. Mik r . Anat., 

 Y. 21, 1882) showed that this secretion was diffused only from certain 

 segments, and that the repugnatory glands, which produce the secretion, 

 open near the middle dorsal line. Haase (SitzuiiL^. b. d. Gesell. naturf. 

 Freunde zum Berlin. Jahrgang, p. 97, 1889) again refers to this curious 

 secretion. In 1S90 W. M. Wheeler reported (Psyche, V. 5, p. 442) this 

 secretion in Polydesmus (Font aria) virgiruettsis, Drury, an abundant 

 species in the middle western States. Early last February, in the foothills 

 near Palo Alto, I collected from beneath stones and logs a number of 

 specimens of Leptodesmus (Polydesmus) Haydenianus, Wood, a common 

 and variable Myriapod in this vicinity, and ranging northward to Oregon. 

 They were collected alive, and when the bottle in which they were contained 

 was opened, the strong and pungent odour of prussic acid was almost 

 overpowering. A chemist friend of mine applied the test, and the result 

 showed free hydrocyanic acid. This test, as given by Wheeler, is quite 

 simple: "A few of the Polydesmi were ground up in a mortar with a 

 small quantity of water. A few drops of potassium hydrate and ferrous 

 sulphate were then added to the solution obtained by filtering the mass. 

 On the application of gentle heat, and the further addition of a little 

 ferric chloride to dissolve the precipitated ferrous and ferric hydrates, the 

 faint but distinct tinge of Prussian blue attested the presence of free 

 hydrocyanic acid." — K. R. Coolidge, Palo Alto, Calif. 



*Pfliiger's Archiv. f. d. ges. Physiol., V. 28, 1882. 



tlndigenous to the Fiji Islands, Moluccas, etc., but now acclimitized in 

 European hothouses. 



Mailed March 6th, 1909. 



