ANNUAL REPORT, 1941 103 



developed from study of the material, and is based on the inherent resistance of 

 the individual bird to growth of the tumor. Thus in diffuse lymphocytoma the 

 host has but little resistance to growth of the tumor, allowing it to assume a 

 diffuse character. In nodular lymphocytoma the host has considerable resistance 

 to growth of the tumor, causing it to be restricted and nodular in form. The 

 combined diffuse and nodular form develops when there is but moderate resistance 

 of the organ or tissue in which the tumor is growing. 



WALTHAM FIELD STATION 



Waltham, Massachusetts 



Ray M. Koon in Charge 



The members of the research staff of the Waltham Field Station are assigned' 

 to the unit by the Departments of Botany, Entomology, Floriculture, Horticul- 

 ture, and Vegetable Gardening. Reports of these departments give results of 

 investigations conducted at this station. 



Soil Testing Service. Testing soil for commercial vegetable growers, mush- 

 room growers, florists, nurserymen, greenkeepers, arborists, vendors of' loam, 

 and home gardeners has long been regarded as an important service which the 

 Field Station has rendered. More recently this program has been extended to 

 include service to the State Department of Public Works, the Metropolitan Dist- 

 rict Commission, Works Project Administration, and town and cit}' administra- 

 tions. There is no doubt that this effort is effective, particularly when the soil 

 test is followed by a personal interview between the client and the technician. 

 The total number of soil samples tested in 1941 was 6676. 



Field Day. The twenty-third annual Field Day on August 6, 1941, attracted 

 the usual number of visitors, about 1200. Perfect weather made it one of the 

 most comfortable Field Days ever held. In an endeavor to increase the interest 

 in the vegetable contests a few more varieties were added to the list. Valuable 

 prizes were offered by the Boston Market Gardeners Association for the three 

 best market packages of Bunched Carrots, Summer Pascal Celery, White Celery, 

 Trellis Tomato, Straightneck Squash, Sweet Corn, and Cucumber. An auction 

 of the vegetables entered in the contests proved an interesting innovation. 



