MISSOURI BOTANICAL GARDEN BULLETIN 41 



give any definite date on which the spraying should begin. 

 The best rule is to begin to spray as soon as possible after the 

 pest is first noticed. Much less spray is needed when the 

 leaves are small and the young caterpillars are more quickly 

 killed. Furthermore, it is extremely desirable to destroy the 

 pest before serious damage to the young foliage is done. The 

 amount of arsenic necessary to kill a full-grown caterpillar 

 apparently varies greatly. It has been estimated, however, 

 that a quantity of the paste equal to 1/2000 of the body 

 weight of the caterpillar will stop its feeding in an hour or 

 two and kill it in a few days. Even though poisoned cater- 

 pillars appear to recover, they often fail to pupate success- 

 fully. 



NOTES 



Dr. E. V. Wilcox, of the agricultural staff of Country Gen- 

 tleman, visited the Garden recently. 



Professor II. M. Hall, of the Carnegie Institution of Wash- 

 ington, recently spent a day at the Garden consulting the 

 herbarium and library. 



On March 10, Dr. Hermann von Schrenk, Pathologist to 

 the Garden, with other members of the Conservation Commit- 

 tee, visited Gov. Hyde in the interest of legislation leading to 

 forest development by the state. 



Mr. G. H. Pring, Horticulturist to the Garden, visited the 

 International Flower Show, at New York, March 18-20, and 

 on March 20 gave an illustrated lecture at the Brooklyn 

 Botanic Garden on "The Missouri Botanical Garden." 



Dr. Hermann von Schrenk attended the Central States 

 Forestry Conference at the Union League Club, Chicago, as 

 a delegate for Missouri and was appointed a member of the 

 executive committee and chairman of the Missouri delegation. 



The fourth number of Volume VII of the Annals of the 

 Missouri Botanical Garden has recently been issued with the 

 following contents : 



"Studies in the Physiology of the Fungi. XI. Bacterial 

 Inhibition by Metabolic Products." W. H. Chambers. 



"The Nutritive Value of the Food Reserve in Cotyledons." 

 B. M. Duggar. 



"Titration Curves of Certain Liquid Culture Media." 

 J. L. Karrer and R. W. Webb. 



"The Use of 'Insoluble' Salts in Balanced Solutions for 

 Seed Plants." B. M. Duggar. 



