LETTER OF TRANSMITTAL. 



U. S. Department of Agriculture, 

 Division of Vegetaule Physiology and Pathology, 



Wa«/if'?igto», I). C, Fehniary iJ, 1900. 



Sir: 1 respectfully transmit herewith a report b}'- Mr. Albert F. 

 "Woods, of this Division, emboch-ino- the results of an investigation of 

 a disease of the carnation, to which he has applied the name "stignio- 

 nose." This disease, which is a serious drawback to the successful 

 growing of the carnation, has until recently been attributed to bacteria 

 and given the name ''bacteriosis." Mr. Woods, however, has shown 

 that it is due to the punctures of insects, principalh^ aphides and 

 thrips, and of mites. Although these are the inciting cause of the 

 trouble, the pathological and physiological changes involved are 

 dependent to a large degree on the condition of the plant and the time 

 the punctures are made. The work deals with the subject largely 

 from the standpoint of pathology and physiology, pointing out the 

 conditions which influence the disease, and suggesting lines of treat- 

 ment based mainly on a knowledge of the proper handling of the 

 plants. We are indebted to Dr. L. O. Howard, Entomologist of the 

 Department, for assistance in a number of matters connected with 

 the work. 



The carnation crop in this country represents an annual value of 

 over $4,000,000 and is constant!}^ increasing. In view of this fact and 

 the man}^ interesting and suggestive points lirought out in the work, I 

 respectfully recommend that the report be published as Bulletin No. 19 

 of this Division. • 

 Respectfully, 



B. T. Galloway, 



Chief of Division. 



Hon. James Wilson, 



Secretary of Agriculture. 



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