48 



In some cases the plants are not taken up in the order of flower- 

 ing — thus the five species of sumac described are given in the 

 chapter for the third week of August and in the same chapter 

 among the ten milkweeds is the Four-leaved Milkweed, the blos- 

 soming time being noted as May-June. The Meadow Sweet 

 {Spiraea salicijolia) is given in the second week of September. 

 The common St. John's-wort in the third week and the Prickly 

 Pear (Opuntia Rafinesquii) the last week in October. 



The book is attractive and wall bring pleasure to many flower 

 lovers and should stimulate them not only in learning the names 

 of flowers but also in learning what insects visit them and how 

 they receive their visitors. Others, interested in making wild flower 

 gardens, may find the notes on propagation of chief interest. 



Root Nodule Bacteria* 



G. T. H. 



In 1932 Fred, Baldwin and McCoy published an extensive 

 work on Root Nodule Bacteria and- Leguminous Plants. Included 

 Was a bibliography as complete as the authors could make it. Now 

 the authors have brought the bibliography up to date with a sup- 

 plement listing nearly 50 titles inadvertently omitted in the original 

 publication and about 500 articles published since 1932. In addi- 

 tion there are indices to the plants and authors mentioned in the 

 original volume. Those who have the earlier publication will want 

 this supplement, which will also be valuable to all those interested 

 in the prol^lems of nitrogen fixation and root nodule bacteria. 



* Supplement to Root Nodule Bacteria and Leguminous Plants. Edwin 

 Broun Fred, Ira Lawrence Baldwin and Elizabeth McCoy. 40 pages. Univer- 

 sity of Wisconsin Press. 1939. $.50. 



