334 NATURAL SCIENCE. may, 



He lived for the day on the promises of the morrow, letting the future 

 take heed for itself. The Museum of Comparative Zoology at 

 Harvard, now ably directed by his son, was the one practical object 

 he set his heart upon, and remains an enduring monument to his 

 vigour and to the " persuasion " that "fondled in his look and tone." 

 His own enthusiasm and reverence for natural objects inspired others 

 "to feel the Seeker's noble zest," but did not always direct and 

 restrain them. Confident in himself, yet longing for the applause of 

 his fellows, he owned a charm that overcame men of all classes : 



" His magic was not far to seek, — 

 He was so human ! . . . Still himself he bare 

 At manhood's simple level, and where'er 

 He met a stranger, there he left a friend." 



Let alone princes and politicians, it is no small thing to say of a man 

 of science that he was the subject of three of the noblest utterances of 

 the poets of his adopted country, Longfellow, Whittier, and Lowell. 



1 In all voices known to her 

 Nature owns her worshipper." 



Methods in Histology. 



F. A. B. 



Leitfaden fur histologische Untersuchungen. By Bernard Rawitz. 2nd 

 Edition. Pp. xiv., 148. Jena : Gustav Fischer, 1895. Price 3 marks. 



The second and improved edition of Dr. Rawitz's treatise on histo- 

 logical methods will be welcomed by all histologists, whether students 

 or researchers. The work is avowedly intended to be a guide to 

 students of vertebrate histology, that is to say, of histology as the 

 word is understood and restricted by anatomists, physiologists, and 

 others who are engaged in studies directly or indirectly connected 

 with medicine. It will, therefore, be of more value to the student 

 or researcher in a medical school than to the general zoologist, who 

 will search in vain for any of those methods, now so numerous and 

 detailed, for killing and preserving animals, marine and otherwise, in 

 as natural and lifelike a condition as possible. Such methods form 

 nowadays a most important part of zoological technique, especially 

 for collectors or marine zoologists. 



Although Dr. Rawitz devotes chapter i. of part i., and a portion 

 of chapter i. in part ii., of his work to methods of studying living 

 material, it is the constituent cells and tissues, while fresh and still 

 living, of higher animals that are included by him under this term, 

 and not the living animal as a whole. In short, this work, as its title 

 implies, is purely and simply histological, and as we have said, 

 histological in the limited sense of the word. Since, however, the 

 greater part, if not all, of the methods given in this book admit of 

 application, with such modification as circumstances may render 

 necessary, to invertebrates as well as vertebrates, the book may be 

 safely recommended to those histologists and embryologists whose 

 studies are not restricted to the latter portion of the animal kingdom. 



The intention of the author has been to make his book, on the one 

 hand, a useful guide to the beginner who, having been through a 

 course of microscopical study, wishes to commence original investiga- 

 tions on his own account, and, on the other hand, a work of reference 

 in which the experienced investigator may find brought together the 

 many important methods of research recommended in scattered 

 memoirs on various subjects. The book is divided into two parts, 

 the first being a classified description of the methods themselves, the 



