Dec, 1921 Bulletin of the Brooklyn Entomological Society 137 



BOOK NOTES. 



The Nature of Animal Light, by E. Newton Harvey, Ph.D. 

 {Monographs on Experimental Biology, J. B. Lippincott Co., 

 Philad-elphia, $2.50). This monograph, while not primarily de- 

 voted to insects, except as they produce light, has considerable 

 of interest to entomologists, particularly coleopterists. Every- 

 one, of course, is familiar with our common fireflies but not all 

 entomologists know what causes them to glow. Nor are insects 

 the only living beings that exhibit light-phenomena. They range 

 from bacteria up the scale of life through various fungi; and 

 from protozoa through fishes. 



Fireflies have a substance which gives off fluorescent light. 

 But in general the light-giving substances in animals are de- 

 pendent on oxygen to produce light. Pyrophorus was studied 

 as early as 1864 by the great Pasteur. The third chapter of 

 this work relates to the physical nature of animal light, many 

 of the animals referred to being insects, principally lampyrid 

 beetles. In fact, as the most easily available material is _ in- 

 sects, every chapter in this highly interesting, though technical, 

 work refers to them. Every student of the Lampyridae should 

 read it. 



Keys to the Orders of Insects, by Frank Balfour Brown, Lec- 

 turer in Entomology in the Univ. of Cambridge (Macmillan, 

 N. Y, $1.50). These keys are primarily for students in courses 

 in entomology at Cambridge University. They apply only to 

 six orders, those most commonly met with — namely, Orthoptera, 

 Hemipte^ra, ,Lepidoptera, Coleoptera, Diptera, Hym'enoptera, 

 the Linnean orders, lacking the Odonata. The keys are in the 

 main founded on previous work and of course are much sim- 

 plified. There are four plates of structures of Lepidoptera, Dip- 

 tera, and Hymenoptera with the parts named. It is not, nor 

 does it purport to be, a new and philosophic scheme of classifica- 

 tion. Melander and Brues' keys are more extensive and more 

 in the line of a classification of the whole class ; these discussed 

 are working keys for the purpose of quickly placing specimens 

 where they belong. For this purpose they are excellent _ and 

 should be a great help to science teachers. To the specialist 

 they ofifer nothing not known heretofore, although they are a 

 part of the Hterature of entomology. 



J. R. T. B. 



