58 MASS. EXPERIMENT STATION BULLETIN 203 



causative agent was isolated from the bronchial tubes and tracheas of infected 

 birds by means of blood agar plates, and transmitted in series to susceptible fowls 

 and roosters, and successfully recovered from each case. 



Culturally, morphologically, and serologically the streptococcus resembles the 

 microorganism isolated from a similar condition in baby chicks reported in Bulle- 

 tin 280, p. 242, 19v32, except that the former organism affected adult birds and the 

 latter was found only in baby chicks. Laboratory studies indicated that this was 

 an instance of biological adaptation which could be changed at will. 



The microorganism isolated in these epizootics is a haemoglobinophilic strep- 

 tococcus and is responsible for a condition which has been called infectious bron- 

 chitis. The prevalence of this disease in the poultry population at large has not 

 been determined. However, laboratory studies indicate that the mortality and 

 loss in egg production may not be as serious as in infectious laryngotracheitis. 



Avian Paralysis or Neurolynipliomatosis. (C. S. Gibbs.) Pathological 

 studies of avian paralysis have been continued through the year, and perivascular 

 infiltration of round cells in the capillaries carrying blood and lymph to the nerves 

 has been observed in incipient stages of the disease. Also metastatic infection of 

 nerves from sarcomas in splanchnic tissue, by means of round cells conveyed in the 

 blood and lymph vessels, has been evident in selected cases. A comparative 

 pathological study of neurolymphomatosis and lymphatic leukemia has been 

 undertaken. Up to the present it has not been possible to differentiate the hyper- 

 plastic tissues in lymphatic leukemia from certain forms of lymphoblastoma, 

 although neurolymphomatosis may be readily differentiated from both on the 

 basis of blood counts, differential blood stains, and gross pathology. 



Cases of neurolymphomatosis from flocks in which the disease has been intro- 

 duced comparatively recently show more inflammation and generalized lesions 

 than those from flocks in which the disease has e.xisted for a number of years. 



WALTHAM FIELD STATION 



(Waltham, Massachusetts) 



Ray M. Koon in Charge 



The research of this Station has been projected principally along the same lines 

 as in 193 L As rapidly as conclusive results on any phase of a project have been 

 obtained, they have been released to the commercial growers for application to their 

 problems, without waiting until the completion of the entire project. For reports 

 on experiments conducted at this Station, in addition to those listed under this 

 caption, see reports of the Departments of Botany, Entomology, Floriculture, and 

 Olericulture. 



An increase of 50 per cent in the total number of visitors to the Field Station 

 was recorded in 1932 over the year previous. During the year 2446 persons came 

 to the Station for personal conferences with members of the staff regarding troubles 

 threatening their commercial enterprises, or in quest of assistance with problems 

 relating to amateur horticulture as it is practiced about the home. Telephone 

 inquiries have numbered 2114; and 2748 letters (not circular) and over 2000 bul- 

 letins, leaflets, and mimeographs have gone out in answer to requests for informa- 

 tion. 



In March a two-day course offered to commercial flower producers anfl retail 

 florists was attended by 225. A school for home gardeners, conducted for two 

 days last April, was attended b^' 800 persons from 54 cities and towns in the 

 eastern part of the State and several cities in Maine, New Hampshire, and Rhode 

 Island. 



