192 



SCIENCE. 



[N. S. Vol. XII. No. 292. 



by inoculation with pure cultures of bacteria 

 obtained from the Cuban leaf, but without suc- 

 cess. Perhaps the most interesting part of Dr. 

 Loew's work is the proof that microbes play 

 no essential part in the normal tobacco fermen- 

 tation, and that the active agents are oxidizing 

 enzymes. These exist in the green leaf, but 

 are able to manifest their peculiar power of 

 utilizing atmospheric oxygen also during curing 

 and fermentation, when unopposed by the nor- 

 mal physiological processes of the living cells. 

 At least three of these are present — an oxidase, 

 a peroxidase and catalase. The documents 

 contain much interesting information on the 

 subject of oxidizing enzymes, together with 

 speculative discussion of their nature and mode 

 of action, which may or may not stand the test 

 of future developments. With the revival of 

 the study of catalytic phenomena now in prog- 

 gress from the standpoint of physical chemistry 

 it is to be hoped that vegetable physiology will 

 not have to wait long for important light on 

 this still obscure subject. 



The documents encourage the hope that the 

 preparation of tobacco, which up to the present 

 has been based on empirical procedure, will be- 

 fore long be conducted in as scientific a manner 

 as is already the case with alcoholic beverages. 

 They also afford an excellent illustration of the 

 manner in which a government department, 

 existing and working solely for practical pur- 

 poses, is nevertheless compelled to encourage 

 studies of broad scientific interest. 



H. N. Stokes. 



The Birds of Eastern North America. Part II, 

 Land Birds. Key to the Families and Species. 

 By Charles B. Cory. lUustr^ed. Special 

 edition printed for the Field Columbian 

 Museum, Chicago. Boston. 1899. Small 

 4to. Pp. 131-387. 



Ornithologists, during the rapid growth of 

 popular bird study in the past few years, have 

 witnessed the production of all kinds of bird 

 literature. In the great variety that has been 

 put forth, the general effort has been for 

 untechnical descriptions with suflScient accuracy 

 to stand the test of practical utility. Mr. Cory 

 has accomplished this end to a considerable 

 degree in several of his books. In the ' Land 



Birds,' we have neither an exhaustive manuaj 

 nor a pocket key, but an easy ornithology for 

 beginners in the shape of a profusely illustrated 

 key. It is continuous in pagination with the 

 volume already published on the water birds 

 and the two are obviously intended to be used 

 together, for the useful introductory preface 

 and glossary of the first part are not reprinted 

 in the second. The book begins with a key to 

 families, illustrated by outlined drawings of 

 bills, wings, tails, and feet, and much reduced 

 halftones of species characteristic of the various 

 families. After this comes the key to species, 

 which is the body of the book ; then follows a 

 systematic list of both land and water birds, 

 giving in general terms the geographic distri- 

 bution of each. The species are divided into 

 groups by absolute characters, such as length 

 of wing and distinctive colors, which could not 

 be misconstrued even by the veriest amateur ; 

 technical terms are avoided as far as possible. 

 The descriptions are brief, scarcely more than 

 diagnoses, but more detailed than those of an 

 ordinary key. The illustrations are not of 

 uniform excellence, but serve their purpose 

 fairly well. They are conveniently inserted in 

 the text which refers to them and are repeated 

 when necessary. The book is a little large for 

 use in the field, but for the actual work of 

 identification at the study table it should be a 

 most valuable aid, particularly to the beginner. 

 W. H. Osgood. 



SCIENTIFIC JOURNALS AND ARTICLES. 



The Journal of the Boston Society of Medical 

 Sciences for June brings the fourth volume to a 

 close and is accompanied by the index. The 

 opening article on ' Pathological Changes affect- 

 ing the Islands of Langerhans of the Pancreas ' 

 is by Eugene L. Opie, and ' The Influence of 

 Defibrination on the Secretion of the Kidney ' 

 is discussed by Franz Pfaflf and Vejux-Tyrode. 

 ' A New Method of distinguishing Human from 

 other Mammalian Blood in Medico-Legal Cases ' 

 is described by Ernest L. Walker, based upon 

 the different characters of the granules of the 

 polymorphonuclear leucocytes of the blood of 

 various mammals and the ability to recognize 

 these differences in dried blood by appropriate 

 treatment and methods of staining. ' Some 



