30 The Microscope. 



forms of animal life to those of a higher and more complicated 

 organization, teaching by outline directions, what to work with, how 

 to work, and more especially, how to observe. 



The introductory chapter deals with methods of collecting and 

 preserving insects, together with a list of the instruments and 

 materials necessary for the prosecution of the work elucidated in the 

 pages following. One especially commendable feature of Mr. Col- 

 ton's book is the reference, at the end of each subject, to works 

 having a particular bearing on the matter under discussion. 



We are always glad to see these practical helps, believing that, 

 if well done, they will do more towards interesting and instructing 

 beginners than any or all of the text-books extant. Teachers will 

 find Practical Zoology just the book to put into the hands of their 

 first course students. 



Modern Petrography, An account of the application of the Microscope to the 

 study of Geology, l>y George Huntington Williams, associate professor 

 in the John Hopkins University. Boston: D. C. Heath & Co. 1886. 



This is the first of a series of essa3^s prepared by specialists 

 which the publishers propose to issue under the title of Moyiographs 

 on Education. 



The microscopic study of rocks is, in this country, a compara- 

 tively new and uncultivated field in microscopic science, and as such 

 offers rich harvests to earnest workers. Microscopy must become as 

 necessary a hand-maid to geology as it is to zoology and botany, 

 and to the microscope we must look to clear up the dark chapters in 

 the history of the earth hidden in its ciystalline rocks. The mono- 

 graph before us gives an excellent introduction to the study. 



A Manual of Microscopical Technology for use in the Investigations 

 OF Mkdicine and Pathological Anatomy, by Dr. Carl Friedlander, 

 University of Berlin; translated by Stephen Yates Howell, M. A., M. D. 

 pp. 249. G. P. Putnam's Sons, New York and London; D. O. Hayaes 

 & Company, Detroit, ]\Iichigau. 



Although a different translation of this well known work has 

 appeared, the one under consideration is to be preferred by the 

 American student, as Dr. Howell has added many notes and much 

 material with a view to adapting it more to the wants and present 

 stage of Microscopical Science in this country. 



We do not think we exaggerate when we say that this little 

 book is probably the best on the subject. Though possessing all the 

 merits of close and careful thought, so characteristic of the Germans, 

 it is happily free from the exasperating prolixity and expanding of 

 trivial detail so common in their works. All departments of the 

 special Technology are carefully considered: The Microscope, choice 

 and use of; instruments, reagents and stainings used in Microscop- 



