AVIAN DISEASES 189 
vancement to these two fields of knowledge. The scientific contribu- 
tions of Neuman on parasites show that such organisms are the cause 
of many a dreadful disease, not only with man and animal, but with 
all avian life. The careful study of their life histories should appeal 
to our protozoologists and inspire them to contribute to our knowledge 
of those parasites which are causing an enormous mortality of our 
most valuable birds. 
After the removal of a sick fowl from the flock a diagnosis 1s 
usually made. Very often the specific organism causing the infection 
is readily discovered, while, on the other hand, the most diligent scien- 
tific efforts may fail to reveal the character of the disease. Many fail- 
ures are accountable because there is a lack of sufficient knowledge or 
a lack of thoroughness in making the investigation. 
The fundamental difficulty in ascertaining more definite knowledge 
about our poultry diseases is the lack of enough scientific men to take 
hold of the situation. To-day we have no rational system of medical 
treatment for birds, nor can one be looked for until scientists, who are 
busy on anatomy and physiology of avian life, offer to the layman a 
definite plan of procedure, when these parasites and bacteria have made 
their way into the body and brought about pathological lesions. 
The relation of bacteriology and parasitology to the infectious 
avian diseases as mentioned before, is fundamental. If bacteriologists 
and protozoologists will enter upon this field of avian diseases as a 
basis for their research in their respective fields, the results of their in- 
vestigations will lead to an improvement in the conditions of our 
poultry yards, and give facts which are necessary before any treatment 
can be found. With men of this character at work upon avian pathol- 
ogy, success is inevitable. 
