117 



Stempell (W.). Notiz uber die Parasiten der Fleckfieberlause. 



[A Note on the Parasites of Lice causing Recurrent Fever.] — 

 Mitt. Zool. Inst, der Westfdlischen Wilhelms-Universitdt, Munster 

 i. W., no. 1, 20th November 1918, p. 6. [Received Tith April 

 1920.] 



With reference to his record of a new parasite, Strieker ia jiirgensi, 

 gen. et sp. n. [R.A.E., B, v, p. Ill] of the clothes louse [Pediculus 

 humanus], the author points out that Kuczynski has infected lice with 

 Bacterium proteus Xi9 [R.A.E., B, vii, 68] and obtained forms very 

 similar to Strickeria, though this resemblance escaped his attention. 



Koch (A.). Zur Atmungs-Physiologie der Larven von Cidex pipiens, 

 L. [The Physiology of Respiration of the Larvae of C. pipiens.] — 

 Mitt. Zool. Inst, der Westfalischen Wilhelms-Universitdt, Munster 

 i. W., no. 1, 20th November 1918, pp. 6-8. [Received 12th April 

 1920.] 



This article repeats the information published bv the author else- 

 where. [R.A.E., B, vii, 49.] 



(loFFERjE (M.) Die Wirkung verschiedener Salze auf Larven von 



Culex pipiens, L. [The etfect of various Salts on the Larvae of 

 C. pipiens.^-— Mitt. Zool. Inst, der Westfdlischen Wilhelms-Uni- 

 versitdt, Munster i. W., no. 1, 20th November 1918, pp. 9-11. 

 [Received 12th April 1920.] 



After it had been found that in larvae of Culex pipiens the method 

 of elimination of carbonic acid (through the surface of the body or 

 through the tracheal system) is not influenced by the gas content of the 

 water, investigation was directed to ascertam the mechanism of the 

 gas interchange and the influence on the working of the tracheae of 

 the variation of the salt content in the medium. Before mideitaking 

 submersion expe inients with solutions containing salts it was however 

 necessary to make comprehensive tests on the life and development of 

 the larvae in solutions containing various salts at different strengths. 



The breeding media to which the larvae were transferred were 

 normal solutions of the chlorides, nitrates and sulphates of sodium, 

 potassium, calcium and magnesium. The average length of life of the 

 larvae was taken as a basis, and observations relating to moulting, 

 pupation and the emergence of adults were taken into account. It 

 was thus possible to divide the solutions into " fatal " (causing death 

 within 24. hours), " development checking " and '" non-active." In 

 the following list solutions of normal strength are taken as a basis and 

 the dilutions mentioned are dilutions of the normal solutions. The 

 first group includes all the solutions at half strength and the quarter 

 strength solutions of the nitrates and of the chlorides of potassium and 

 magnesium. Except in the case of potassium nitrate all the salts at a 

 strength of /^ or ^^ were non-active ; common salt (sodium chloride) 

 was inactive at /g strength. Development was checked by the chlorides 

 and sulphates of sodium and potassium. In sodium chloride solutions 



