185 



with tubes about 24 in. long and 40 minutes with tubes of about 

 11 in. These tests prove the dependence of the pupae on the 

 amount of oxygen dissolved in the submersion medium and, therefore, 

 the fact of respiration through the skin. In spite of this, submersion 

 causes the pupae to die more quickly than the larvae owing to lack of 

 intestinal respiration and because they have a greater need for oxygen, 

 which Weinland believes to be connected with the building up of fat 

 during pupation. 



In water containing much CO2 (O'S gm. per litre), gas bubbles appear 

 at the tips of the pupal spiracles and are slowly reabsorbed by the 

 liquid. In this respect the pupae differ from the larvae ; Koch found 

 no bubble production in the latter. 



The length of life when submerged in salt solutions is shorter than 

 in pipe-borne water. Tlie most marked effect of salts on larvae sub- 

 merged in them was the production and delivery of gas bubbles at 

 the abdominal spiracles in the case of C. pipiens and T. anniilata. 

 This was not seen in Anopheline larvae. The number of bubbles 

 varies with the composition and concentration of the fluid. Nitrates 

 were the most active ; these were followed by the chlorides and then 

 by the sulphates. Among the latter, magnesium sulphate was an 

 exception, behaving like the nitrates. Gas bubbles may be produced 

 by solutions weaker than those causing death. The bubbles must 

 consist of used air, i.e., COg, perhaps mixed with nitrogen from 

 atmospheric air. The mechanism of this carbonic acid excretion is 

 discussed. 



No bubbles are formed or delivered in the case of Anophelines, 

 because the body- wall is highly permeable to this gas. Larvae of 

 Culex and Theobaldia, especially in the older stages, show gas bubbles 

 in salt solutions, but not in water free from salts or in water rich in 

 CO2. Under normal conditions intestinal respiration probably suffices 

 for excreting the gas. 



As there is no reason to think that under normal conditions the 

 excretion of CO2 takes place in a different manner, these data should 

 apply to Cuhcid larvae imder all natural conditions except when a 

 moult is imminent, when part of the carbonic acid must be eliminated 

 through the spiracles. 



The pupae of Culex behave in the same manner as the larvae of 

 Anopheles. No gas bubbles are given off in salt solutions, but bubble 

 formation and delivery occurs in water rich in COg. 



Koch (A.). Die Atmung der Culiciden-Larven. Weitere Studien an 



Mochlonyx vehitina (Ruthe). [The Respiration of ("ulicid Larvae. 

 Further Studies on M. velutinus.] — Mitt. Zool. Inst. Westf. 

 Wilhelms-Univ., Miinster i. W., no. 3, 5th August 1921, pp. 31-41. 



These studies on the larvae and pupae of Mochlonyx velittiniis, Ruthe, 

 continue experiments already noticed [R.A.E., B, viii, 118]. The 

 salts were the same as those used in the preceding paper. Sodium 

 chloride was found to have the most injurious effect, and evidence was 

 obtained that light is injurious to both larvae and pupae. 



Fillers (A. W. N.). Sarcoptic Scabies (or Itch) in the Chimpanzee.— 



Vet.Jl. London, Ixxvii, no. 9, September 1921, pp. 329-333, 3 figs. 



There appears to be no previous record in existing literature of 

 scabies in the chimpanzee. Many of these animals imported from 



