86 



native tree to Blakeslee and Jarvis, New England Trees inWinter, 

 similarly for nearly every cultivated shrub or tree given references 

 are made to the pages in Schneider's Dendrolische Winterstudien. 

 The names used are those given in Bailey's Cyclopedia of Hor- 

 ticulture. For many of the species one, and only one, common 

 name is given, other species have only the scientific name. A 

 freer use of common names and synonyms for frequently used 

 scientific names would have added to the value of the book. 



The book will fit the coat pocket comfortably. The dark 

 brown cover offers little contrast to the black lettering on it, 

 otherwise no fault can be found with the appearance of the book 

 as it is well printed on good paper and bound in flexible cloth. 

 Within the limits of so small a book it is surprising how much 

 has been included. The book will prove almost invaluable to 

 those who wish to determine trees and shrubs in winter. 



George T, Hastings. 



PROCEEDINGS OF THE CLUB 



Meeting of March id, 1925 



This meeting was held at the American Museum of Natural 

 History at 8:15 p.m., with Vice President Richards in the chair. 

 The attendance was 22. 



Dr. George H. Shull, of Princeton University, gave a lecture 

 on "Genetical Studies in Oenothera." 



The lecturer remarked the extensive work which has been done 

 on the genetics of Oenothera by de Vries, who is still vigorously 

 engaged at the work which he began 40 years ago, and by nu- 

 merous investigators who have joined him in recent years, the 

 lecturer's own work having been continued now for a period of 

 20 years. Examples were given to illustrate the two most fun- 

 damental peculiarities of Oenothera genetics, the production of 

 unlike reciprocal hybrids and the splitting in Fi to form the so- 

 called "twin" hybrids. 



Diagrams were displayed representing the manner in which 

 two sets of balanced lethal factors account for the fundamental 

 peculiarities of genetical behavior in the Oenotheras, the La- 

 marckiana type being characterized by a double pair of zygote 

 lethals which account for the Fi splitting, the biennis type by a 



