NEUROLYMPHOMATOSIS IN CHICKENS 



13 



of the celiac plexus aiul o\'ariaii ner\e appeared to be primar\-, while the other 

 neurohniphomas and l\niphoc\tonias were undoubtedly established as a result 

 of metastasis. All of the neurohniphomas in the celiac, sciatic, and brachial 

 nerves of Flock D appeared to be of primar\- origin and led to the formation of 

 h mphocytomas in the ovary and muscles of the legs and wings by direct infiltra- 

 tion. The malignant growths in other tissues appeared to be of perivascular 

 inception. Figs. 7 and 8 show peri\ascular infiltration of the sciatic nerves. 



In studying these cases it was not always possible to determine whether the 

 nerves or the visceral organs were affected first, although it was demonstrated 

 that metastasis as well as direct infiltration may take place through the nervous 

 s\stem, for the pathological cells appeared to be carried in the capillary spaces. 

 This explains wh>" the connecting link between neurolyniphoma and hniphocx- 

 toma appeared to be the branches of the larger nerves leading to the visceral 

 organs, and other tissues in which the neoplasms were found. While distant 

 metastasis undoubtedly occurred in some cases, the evidence was not as con- 

 vincing as in those instances in which direct infiltration or metastasis was traced. 

 Apparently the pathological cell responsible for these malignant growths occasion- 

 ally dex'elops such invasiveness that an>' or all tissues are affected. If this 

 deduction is correct, neurohniphomatosis and hmphocytomatosis are closelv 

 related and are differentiated on the basis of tissue selection only. Furthermore, 

 this stud}' indicates that neuroKniphomatosis is a disease of >oung birds while 

 lymphcc>tomatosis is more commonh' found in adults ten months or more of 

 age. However, in spite of the conclusiveness of these histological studies, the 

 exact relation between neurohniphomatosis and lymphoc>tomatosis awaits 

 etiological confirmation, if the theory of an inciting virus is accepted. 



The Mortality and Morbidity of Flock C 



Next an attempt was made to determine the mortalit\" and morbidit\" occurring 

 in Flock C from all causes. The results of this stud\' are shown in Table 4. 



T.VBLF. 4. A Study of Mort.\lity .\xd Morbidity in Flock C 



Diseases 





Neurolymphomatosis with Gross Lesions 



Avian Paralysis without Gross Lesions 



Lymphocytomatosis 



Neurolymphomatosis and Lymphocytomatosis 



Myelcleukosis 



Erythroleukosis 



Myeloleukosis and Lymphocytomatosis 



Chronic Coccidiosis 



Slipped Tendon 



Ascariasis 



Visceral Gout 



Cannibalism 



53 



38 



9 



23 



3 



9 



14 



Indefinite 



Indefinite 



Indefinite 



Indefinite 



