(slit open 

 lengthwise) 



Horinal glandular 

 Structures 



Small intestine 



i — Normal 

 cascum 



identify the condition positively as blackhead a dead turkey 

 should be opened. 



Organs diseased. — In examining the organs of a turkey which 

 has died of blackhead the most prominent feature is usually the 

 occurrence of gray or yellowish spots on the surface of the liver. 



These are readily seen and measure from a very small fraction 

 to three-fourths of an inch across, (See Fig. 1.) The disease does 

 not start in the liver, however, but in a certain portion of the 

 gut (intestine) . If the course of the latter is followed throughout 

 its length it will be found that in the lower portion two blind 

 tubes are given off, one on each side, which extend along the 

 intestine to which they are attached (see diagram, Fig. 2). 

 These blind pouches, or 

 cffica, as they are called, 

 are of considerable size, 

 being about a foot long in 

 an 8 to 10 pound turkey. 

 While they, like the human 

 appendix, are prone to dis- 

 ease, nevertheless, they are 

 doubtless of greater impor- 

 tance in the processes of 

 digestion. It is in these 

 caeca, towards their blind 

 ends, that blackhead always 

 starts, and an examination 

 of these organs will always 

 show in this disease a thick- 

 ening of the wall, together 

 with a change of color and 

 opacity suggesting an ab- 

 scess. Either one or both 

 caeca may show disease af- 

 fecting a spot, at times the 

 size of a dime, or again, 

 involving the greater por- 

 tion of the wall. The cavity 

 of the diseased caecum is in some cases filled with a tough 

 yellowish colored "core," or with soft, reddish gray, foul-smelling 

 material. 



Membranous attach- 

 ment of 



Diseased 

 portion 



Diseased 



csecum 



Large intestine 



Fig. 2. — Diagramatic sketch, showing the two 

 caeca attached throughout their length to the 

 small intestine by a thin membrane. The 

 caecum on the left is represented as slit open to 

 show its inner surface and a diseased spot; the 

 caecum on the right is normal and unopened. 



