LITERARY NOTICES. 



275 



evolutions called the Irving School March 

 Drill. An illustrated chapter is devoted to 

 Delsartean posturing. Apparatus drills with 

 wands, Indian clubs, rings, dumb-bells, etc., 

 are described, and a great many additional 

 evolutions are suggested. The volume in- 

 cludes thirty-two pages of music suitable for 

 evolutions of classes. We are somewhat as- 

 tonished to see in the front of the book a 

 poetical quotation ascribed to Herbert Spen- 

 cer! 



Mineralogy. By Frederick H. Hatch, F. 

 G. S. New York : Macmillan & Co.- Pp. 

 124. Price, $1. 



This is a brief elementary manual con- 

 sisting of two parts, the first devoted to 

 characters of minerals, and the second being 

 descriptive. In the first part the crystalline 

 forms of minerals are described quite fully, 

 and the chemical composition, specific grav- 

 ity, and other characters are treated briefly. 

 In the descriptive part the minerals are 

 grouped under these heads : rock-forming 

 minerals, ores and veinstones, salts and other 

 useful minerals, gems or precious stones. 

 The text is illustrated with many cuts show- 

 ing the forms of crystals or amorphous min- 

 erals and the occurrence of minerals in veins. 



A Treatise on Hygiene and Public Health. 

 Edited by Thomas Stevenson, M. D., and 

 Shirley F. Murphy. Vol. I. Philadel- 

 phia: P. Blakiston, Son & Co. Pp. 1013. 



The extensive work of which the first in- 

 stallment is before us is made on the plan of 

 having the several subjects included in its 

 scope treated by authors having special quali- 

 fications for their respective tasks. In the 

 selection of subjects the editors have been 

 guided mainly by the needs of the English 

 officials known as Medical Officers of Health, 

 but there is much information in the essays 

 which is applicable to sanitary conditions the 

 world over. The first volume comprises six- 

 teen essays dealing separately with air, 

 water, food, clothing, baths, the dwelling, 

 physical education, offensive and noxious 

 businesses, etc. The most space is given to 

 the treatise on The Dwelling, by P. Gordon 

 Smith and Keith D. Young. The authors 

 deal with the subjects of site, the arrange- 

 ment of laborers' dwellings, prisons, bar- 

 racks, schools, workhouses, and hospitals, 



both general and special, and the drainage 

 of the dwelling. The Disposal of Refuse is 

 also treated with much fullness in a separate 

 article by W. H. Corfield, M. D., and Louis 

 C. Parkes, M. D. In the essay on Warming 

 and Ventilation, the author, W. N. Shaw, 

 F. R. S., gives formulas and describes 

 methods for calculating the movement of 

 air in various systems of ventilation, and 

 gives a summary of the conditions to be 

 satisfied to secure a proper change of air. 

 He also compares the efficiency of the ordi- 

 nary modes of heating, and gives various 

 numerical data concerning heating in the 

 climate of England. The volume is illus- 

 trated with nearly two hundred cuts and 

 plates, and has a separate index. 



Animal Coloration. By Frank E. Beddard, 

 M. A., F. R. S. E. New York : Macmillan 

 & Co. Pp. 288. Price, $3.50. 



Mr. Beddard has chosen a very attractive 

 topic, and has made a book interesting to 

 both the zoologist and the general reader. 

 After an introductory chapter giving the 

 principal facts of animal coloration, he cites 

 a number of cases in which the coloration 

 of an animal appears to be in part due di- 

 rectly to the influence of the surroundings, 

 among which are the prevalence of green in 

 the animals of verdant Ceylon, the white fur 

 of polar animals, and the absence of color 

 among cave-dwelling species. Coming to the 

 purposes of color in animals, the author 

 finds much to discuss under the head of pro- 

 tective coloration. While on this subject he 

 raises the question whether as a matter of 

 fact animals are concealed from their foes 

 by their protective resemblances, and shows 

 that there is much evidence on the negative 

 side. He contends, also, that in some cases 

 so-called protective coloration is produced 

 more simply and directly than by the opera- 

 tion of natural selection. Warning colora- 

 tion, first explained by Mr. Wallace, next re- 

 ceives attention. The author is inclined to 

 give much weight to the suggestion of Dr. 

 Eisig that in caterpillars which are distaste, 

 ful to their enemies the usual bright pig- 

 ments cause the inedibility of the species 

 instead of being produced to advertise it. 

 Alluring colors receive attention in the same 

 chapter. Allied to coloration like the sur- 

 roundings is mimetic coloration or resem- 



