NOTES AND LITERATURE. 

 ZOOLOGY. 



Temperature of Insects. — Professor Bachmetjew's ' paper is one 

 of those rare publications which is full of interest not only to the 

 specialist in entomology but to biologists in general. The Russian 

 author, with the equipment of the trained physicist, approaches a 

 subject that has often been studied before, and after treating it in an 

 exhaustive manner reaches new and important results, which would 

 carry conviction in their very simplicity, even if they were not sub- 

 stantiated step by step by detailed tables of observations. The work 

 of all previous investigators in determining the vital temperature of 

 insects is briefly and critically reviewed as a preface to each of the 

 main sections of the work. 



In order to determine the temperatures, the insect was spitted 

 through the thorax on a thermoelectric needle consisting of fused 

 manganin and steel wires connected with a galvanometer. A detailed 

 account of the somewhat complicated apparatus and the method of 

 using it are given in an appendix (pp. 13S-142). A number of 

 different insects, mostly larger moths, butterflies, and beetles, both 

 pupal and imaginal, were used in the experiments. 



The first part of the work is devoted to a consideration of the body 

 temperature of insects. In his earlier experiments, Bachmetjew came 

 to the conclusion that the temperature of the insect body varies within 

 very considerable limits, apparently without any serious consequences 

 to the life of the animal. He found, moreover, that in resting insects 

 the temperature is the same or very nearly the same as that of the 

 surrounding air. Subsequent experiments, however, led him to con- 

 clude that this is true only under ordinary conditions of moisture, 

 temperature, etc., since these factors, when abnormal, have a very 

 pronounced effect on the body temperature. Under normal condi- 

 tions, when the temperature of the atmosphere is raised, the tempera- 

 ture of the insect, though rising, lags at first more and more behind 



^ Bachmetjew, P. Temperaturverhaltnisse bei Insekten. Experimentelle ento- 

 mologische Studien vom physikalisch-chepiischen Standpiinkt aus. Bd. i, pp. 4- 

 i6o. Leipzig, Wilhelm Engelmann, 1901. 



401 



