35 



carbon monoxide leads to results similar to those obtained with 

 tobacco smoke, etc. Molisch considers the data inadequate, 

 however, for determining what constitutes the effective ingredient 

 or ingredients of tobacco smoke. 



Older plants generally are much less affected by tobacco 

 smoke than seedlings. A number of specific peculiarities are 

 encountered, however. In Goldfussia glomerata lenticel forma- 

 tion is induced; Syringia vulgaris, Rosa, etc., shed their leaves 

 (spring time) after about two days' exposure to tobacco smoke. 



W. G. M. 



Plant Breeding in Scandinavia. By L. H. Newmann. Pub- 

 lished by the Canadian Seed Grower's Association, Canada 

 Building, Ottawa, Canada, Price $i.oo net (cloth $1.50). The 

 plant breeding station of The Swedish Seed Association at Svalof 

 is now generally recognized as one of the foremost stations in the 

 world for the practical and scientific breeding of the cereals. 



Mr. Newmann has recently spent about nine months at 

 Svalof where he studied the methods of work and examined the 

 various printed and private records of the investigations. This 

 personal experience enables him to perform a distinct service in 

 presenting the work of the station in book form to English reading 

 students. 



The main divisions of the volume are as follows: I, Introduc- 

 tion; II, The Swedish Seed Association (general resume); III, 

 The System of plant improvement at Svalof and its development; 

 IV, The composition of a race of cereals and its variability; V, 

 Practical application of principles now recognized in cereal 

 breeding at Svalof; VI, Methods of work in cereal breeding at 

 Svalof; VII, Summary of work done with different crops and 

 results obtained (wheat, barley, pease, clovers, grasses, and 

 potatoes); VIII, Appendix; IX, Literature cited. 



A brief synopsis of the points that are of special interest can 

 be grouped under the following heads : 



Methods and Results 

 The method of "mass selection'' is still used in maintaining 

 purity of sorts, and as preliminary to "line culture" and hybridi- 

 zation. 



