Year 

 (Sept. 1- 

 Aug. 3n 



ANNUAL REPORT, 1940 25 



Summary of Service Bacteriology — 1928 to 1940 



Paid Examinations 



i-c-liar|re Exaniinat 



Misc. Totals 



Tot 



Total 

 Exaniitiations 

 s foi- the Year 



i;>2»-3() 

 1930-31 

 1931-32 

 1932-33 

 1933-34 

 1034-3.0 

 193r)-3G 

 193 0-3 7 

 193 7-3 S 

 tl93S-39 

 tl939-4() 



106 



lis 

 130 



2 23 

 314 



256 

 499 

 .504 

 410 



,210 



91S 

 ,054 



,683 

 ,849 



740 



6 53 

 326 



196 

 251 

 304 

 389 



3 82 



694 

 335 

 320 



1.32S 

 1,059 

 1,248 

 1,516 

 1,535 



1,815 

 1,571 

 1,240 



Totals .. 9,001 

 Grand Totals 13,24S 

 (Paid and 

 N'o-(liarg:e) 



1,32.- 

 1.58* 



2,688 

 2,861 



173 4,684 



*Cheniical analyses. 



tThis sudden decline in the number of samples (mostl 

 the in-stallation of several municipal and private lahoratoi 



ilk ) can be traced directly to 

 in this part of the state. 



DEPARTMENT OF BOTANY 

 A. Vincent Osmun in Charge 



Diseases of Trees in Massachusets. (M. A. McKenzie and A. Vincent 

 Osmun.) 



The Dutch Elm Disease Problem. State-wide interest in the Dutch elm 

 disease was intensified during 1940 as reports of affected trees in Columbia 

 County, New York, and Litchfield County, Connecticut, established new 

 stations for the causal fungus, Ceratostomclla ulmi (Schwarz) Buisman, in 

 areas immediately adjacent to the west and south of Massachusetts' 

 boundaries, and the total number of trees found to be infected in the 

 United States rose to 61,391. At the present time (December 2, 1940), 

 no positive proof of the disease in the elms of Massachusetts has been 

 established although hundreds of suspected trees have been checked in 

 field and laboratory studies during the past year. 



Tlie W'Ork of the organized project of this Station in collecting and 

 studying specimens from trees showing symptoms macroscopically indis- 

 tinguishable from those of the Dutch elm disease has been supplemented 

 by other public and private groups and individuals, including the Massa- 

 chusetts Department of Agriculture, United States Department of Agri- 

 culture, The Massachusetts Forest and Park Association, town and city 

 tree wardens, employees of other municipal and State departments, arbori- 

 culturists, and private citizens. Recently in cooperative investigations the 

 Director of Plant Pest Control of the State Department of Agriculture 

 has seen fit to invoke the provison of the Massachusetts statute for the 

 destruction of trees infested with carrier insects of the causal fungus in two 

 instances where elms were believed to be dangerously threatened by the 

 disease. Connecticut, however, remains the only New England State in 



