POULTRY DISEASES AND THEIR TREATMENT. 183 



dom ; these are the protozoa, the lowest animal forms. The oth- 

 er two groups of micro-organismal agents of enteritis are found 

 in the plant kingdom ; they are bacteria and molds. Hence, the 

 3 groups of microscopic agents of intestinal inflammation are 

 protozoa, molds and bacteria." 



It is doubtful if many of the cases of true white diarrhea are 

 caused by the physical or mechanical agents mentioned in Dr. 

 Morse's first two classes. In most cases true white diarrhea 

 appears to be an infectious disease. Such disease we know is 

 caused by some form of parasitic organism. Without doubt 

 improper incubation, brooding and feeding, resulting in weak- 

 ened chicks, very often lay the foundation for the attacks of 

 parasitic organisms. In many cases these faulty methods of 

 handling the eggs and chicks appear to be the real cause of the 

 disease while they are really only indirect causes. 



From this it should not be understood that such things as poor 

 food, poor brooding and weakened breeding stock are of no 

 importance in the study of white diarrhea. It is just exactly 

 these predisposing factors which result in chicks with weak con- 

 stitutions, easily overcome by disease germs. Without doubt the 

 points at which most progress can be made in combatting such 

 diseases are in the methods of incubation and in the care of 

 the chicks for the first 3 weeks of their lives. Nevertheless 

 it should not be forgotten that the death of the chick is caused 

 by the ravages of some minute parasitic organism. 



Within recent years several investigators have discovered 

 organisms which they believe to be the specific cause of white 

 diarrhea. Three of these may be mentioned at this place : ( i ) 

 Coccidium tcnellum or cunicuH producing the disease called 

 "coccidiosis." (2) Bacterium puUorum producing "'bactillary 

 white diarrhea" and (3) Aspergillus fumigatus and allied spe- 

 cies, producing aspergillosis or brooder pneumonia of chicks. 

 Of these the first two diseases will be considered in some detail 

 in the following paragraphs. Aspergillosis is treated in a sepa- 

 rate section of this chapter (cf. p. 193). 



Intestinal Coccidiosis. 



In Circular 128 of the Bureau of Animal Industry, U. S. De- 

 partment of Agriculture, Dr. G. B. Morse published a prelim- 

 inary account of some investigations on the cause of white diar- 

 rhea. Microscopic examination of the intestines of chicks dying 



