July 5, 1895.] 



SCIENCE. 



21 



— as the Cetaceans, Edentates and their al- 

 lies, and others. While it has been deemed 

 useful, especially in an American review, to 

 point out the most conspicuous errors in 

 the treatment of the American members of 

 the perplexing order Rodentia, it must not 

 be supposed that other parts of the book are 

 equally open to criticism. In reviews it is 

 both proper and desirable to point out er- 

 roneous statements, while, fi-om the nature 

 of the case, like detailed comment respect- 

 ing the good qualities is well nigh impossi- 

 ble. Hence notices of very good books of- 

 ten seem to consist mainly of adverse criti- 

 cism. I fear this is true in the present in- 

 stance. 



The bu'd pai't of the Eoyal ISTatural His- 

 tory will be reviewed separately. 



C. H. M. 



Lehrbuch cler Biologie der Pflanzen. Feied- 

 RiCH LuDWiG. Stuttgart, Verlag von 

 Ferdinand Enke. 1895. 8°, pp. vi + 

 604, with 28 figures in the text. 

 The Germans are quite persistent in re- 

 fusing to recognize as biology the mixture 

 of botany and zoology, which is rather un- 

 fortunately called biology by the English 

 and Americans, and as a general thing they 

 designate by the latter name the relations 

 of plants to their surroundings, a subject 

 that the Madison Congress of American 

 botanists agreed to call ecology. It is, 

 therefore, to this subject that Professor 

 Ludwig's latest book refers, and it in- 

 cludes chapters on the adaptations of land 

 and water plants to their surroundings, 

 adaptations to a parasitic habit of life, the 

 part played by fungi in the nutrition of 

 higher plants, carnivorous plants," commen- 

 salism and symbiosis, adaptations of plants 

 to the physical and chemical character of 

 the soil, climbing plants, phenology, the 

 various protective devices met with in 

 plants, the many interesting arrangements 

 concerned with pollination and dissemina- 



tion, and the influence of man on the forms 

 of plants, with which is connected a general 

 discussion of heredity and the causes of 

 variation from hereditary types. 



Dr. Ludwig is an earnest student of the 

 relations of plants to their surroundings, 

 especially of their adaptations to pollination 

 by insect agency, and his book appears to 

 be not only pleasantly written, but accurate 

 in its statement of fact. 



Wm. Trelease. 



A Monograph of the North American species of 

 the genus polygonum : By John Kunkel 

 Small. Memoirs from the Department 

 of Botany of Columbia College, Vol. I. 

 Issued April 23, 1895. 4°. pp. 183, PL 

 A. and 84. Price $6.00. 

 While it is generally believed that the 

 classification and naming of plants is a less 

 advanced branch of botanical investigation 

 than the study of their morphology, devel- 

 opment and physiologj', botany would be a 

 very crude science, indeed, without such 

 work, and one of the duties that fall to 

 the possessors of every large herbarium is 

 that of monographing difficult groups — a 

 duty all the more imperative because of 

 the undeniable fact that such work can only 

 be done where good library and herbarium 

 facilities are at hand. 



The botanical department of Columbia 

 College, with one of the finest herbaria and 

 systematic libraries in the country, is ap- 

 parently fully aware of this fact, and at 

 frequent intervals Dr. Britton and his as- 

 sistants and special students publish revis- 

 ions that are helpful to all systematic stu- 

 dents of the North American Flora. The 

 last of these publications inaugurates a 

 series of Memoirs which promise to reflect 

 much credit on the institution under the 

 auspices of which they are published. 



No collection in the world contains more 

 valuable material for a study of the North 

 American Knotweeds than is to be found at. 



