SCIENCE— ADVERTISEMENTS 



HUGO DE VRIES IN AMERICA 



Professor Hugo De Vries is now in this country on a tour of investigation and 

 study of the relations of the flora to the geological and geographical conditions in 

 certain localities. He delivered the dedicatory address of the Rice Institute, 

 Houston, Texas, on October 14th. Other places he will visit are Dixie Landing, 

 Alabama, where he goes with Professor Tracy to visit the type locality of Oeno- 

 thera grandiflora to study its possible mutants in its original habitat, Biloxi, 

 Mississippi. He will make his headquarters there while he visits the "Mud Lumps' ' 

 near the mouth of the Mississippi River, and a number of Islands near Biloxi. 

 After that he and Professor Tracy will go to San Antonio, Brownsville, and other 

 points in Southern Texas. 



The presence in this country of the great Dutch botanist and writer lends im- 

 portance to the authoritative translations of his important works recently added to 

 the Open Court list of publications. 



The additions made by De Vries in the field of research covered by Darwin 

 have become an essential part of all modern thought relating to heredity, descent 

 and the origin of species. 



His literary work has the qualities of directness, simplicity and practicality 

 rare in scientific writers. It is fascinating to the general reader and should be as 

 much a part of the equipment of the amateur, the practical farmer and the horti- 

 culturist as of the trained biologist. 



FOUR IMPORTANT BOOKS BY HUGO DE VRIES 



The Mutation Theory 



(Two Volumes) 

 Experiments and Observations on the Origin of 

 Species in the Vegetable Kingdom. 

 Translators Professor J. B. Farmer and A. D. 



Darbishire 

 583 pp. 114 illnstrations. Six colored plates 



(lithographs) . Bibliography and index. 

 2 Vols. Price, $4.00 per volume net. 



A knowledge of the laws of mutation must 

 sooner or later lead to the possibility of inducing 

 mutations at will and so of originating perfectly 

 new characters in animals and plants. And jnst 

 as the process of selection has enabled us to pro- 

 duce improved races, greater in value and in 

 beauty, so a control of the mutative process will, 

 it is hoped, place in our hands the power of origi- 

 nating permanently improved species of animals 

 and plants. 



Species and Varieties: 

 Their Origin by Mutation 



Second Edition, thoroughly Corrected and 

 Revised, with Portrait 



Price, postpaid 



$5.00 



830 pp. 8vo, cloth. 



The contents of this book include a readable 

 and orderly recital of the facts and details which 

 furnish the basis for the mutation-theory of the 

 origin of species. All of the more important 

 phases of heredity and descent come in for a clari- 

 fying treatment that renders the volume ex- 

 tremely readable to the amateur as well as to the 

 trained biologist. The more reliable historical 

 data are cited, and the results obtained by Pro- 

 fessor De Vries in the Botanical Garden at Amster- 

 dam during twenty years of observations are de- 

 scribed. 



Intracellular Pangenesis 



300 pp. Cloth, $3.00 



The whole science of vital phenomena is con- 

 tained in what De Vries calls ilie Pangen, a special 

 hereditary character, which may be made the ob- 

 ject of experimental treatment in animals as well 

 as in plants. It is a most attractive theory, and 

 the book is so truly scientific in its simple lan- 

 guage and reverential spirit as to be easily read and 

 understood by the laymen in science as well as 

 the scholar ; and the preacher as well as the 

 plant breeder will find in it many fine in- 

 spirations. 



The third part of the book consists of a chapter 

 on Fertilization and Hybridization. 



Supplied by your bookseller or mailed upon receipt of price, by 



OPEN COURT PUBLISHING COMPANY <■" ^ cHfc'loo''^'"''' 



Plant Breeding 



Comments on the Experiments of 

 Nilsson and Burbank 



A scientific book in simple language. Intensely 



interesting as well as instructive. Of special 



value to every botanist, horticulturist 



and farmer. 



360 pp. Illustrated with 114 beautiful half tone 



plates from nature. Printed on fine paper 



in large type. Cloth, gilt top. 



Price, $1.50 net. Mailed, $1.70 



