NEUROLVMPHOMATOSIS IN CHICKENS 3 



were inoculated intravenousK^ w ith Berkefeld \' filtrates of the neoplastic lesions 

 of nerve tissue, which had been ground up in a sterile mortar with a sterile pestle 

 and sand. Also, fresh lymphocytomas were transplanted into the visceral organs, 

 muscles, and skins of 140 chickens, by means of a sterile trocar. These chickens 

 were held for six months without showing an}- symptoms or lesions of lymphoc}- 

 tomatosis, a disease closeK' related to, if not the same as, neurolymphomatosis. 



The stock for these etiological experiments was selected from 10 different flocks 

 and an attempt was made to avoid chickens previously exposed to the disease, 

 as such exposure might lead to erroneous results. Acti\e s\'mptoms of neuro- 

 hmphomatosis do not appear for two or three months after infection has taken 

 place. This precaution was deemed necessar\- because in some of the earlier 

 experiments of the writer the same number of controls as inoculated birds came 

 down with symptoms and lesions of neuroKmphomatosis, indicating that the 

 birds had pre\'ioush- contracted the disease. 



Also it was found in the course of these experiments that chickens inoculated 

 intraperitoneally and intramuscularly with suspensions of neurohmphomas, 

 pyogenic bacteria, and tar developed tumors of the peritoneum, visceral organs, 

 mesentery, muscles, celiac plexus, and small ner\-es of the visceral organs in- 

 distinguishable from hmphoc\tomas and neurohmphomas of spontaneous 

 origin. Ruptured egg sacs and oviducts were believed to be responsible for 

 similar conditions in spontaneous cases by first establishing peritonitis, which 

 ultiniateK- led to tumor formation. 



The results of these laboratory transmission experiments are inconclusixe, 

 and in \iew of the work that has been done b\' Seagar (1933), Lerche and Fritzsche 

 (1933), and Mcintosh (1933) should not be considered final until further work 

 has been done, because there are so many unknown factors associated with the 

 etiology of neuroKmphomatosis and h"mphoc\tomatosis that it is doubtful 

 whether any investigator has succeeded in keeping them all under control. How- 

 ever, persistent trial and error, of which this study is a beginning, should not 

 onh' re\eal the etiology of these two diseases but show their relation, if any, 

 to 1\ nipholeukosis. 



The Development of Histologica! Methods 



Plenty- of material from spontaneous cases has been a\'ailable for hematological 

 and histopathological studies. It has been possible to select material from 

 flocks of which the history was known, and the studies for the most part have 

 been confined to one of these flocks for a period of four \ears. The first two 

 years were devoted largeh" to developing staining methods, acquiring a familiarity 

 with the histological elements in poultry pathology, and different iating neuro- 

 lymphomatosis from other diseases to which it appeared at first to be more or 

 less related in spontaneous cases. 



The blood staining methods suggested by Furth (1931), the bone marrow 

 studies of Forkner (1929). and Mallory's (1921) eosin and methylene blue and 

 phosphotungstic acid hematoxylin stains for tissues were especially valuable in 

 the development of histological methods for this stud\-. Wong's (1928) method 

 for the determination of hemoglobin was used. The blood clotting time was 

 estimated by the method of Wright (Morse and Loone\-, 1927). 



It was found that the thrombocytes could not be counted with any degree of 

 accuracy unless supravital staining was emploxed. Hence the counts for throm- 

 bocvtes are omitted in this bulletin. 



