NINTH ANNUAL REPORT. 149 



of the red corpuscles can take place, hence more or less anaemia 

 must be expected as a direct sequence of these lesions. 



Another type of changes found partly in the same skeleton as 

 the above, and also alone in separate cases, comprises the altera- 

 tions described as typifying true osteomalacia. In these bones 

 lacunar absorption is not apparent, but instead the marrow is 

 limited ofif from the compact tissue by a relatively normal endos- 

 tium which encloses no osteoclasts but internal to which is found 

 a layer of osteoid tissue, possessing all the organic structure of 

 normal bone, but from which the lime salts have been removed. 

 Except in this one particular the tissue seems in many ways to 

 be normal (see plate 5, Fig. C). In places, however, the osteoid 

 layer, particularly about the larger Haversian canals, is becom- 

 ing infiltrated by large polygonal cells, small round cells, and 

 new blood vessels are beginning to form from those originally 

 in the Haversian canal (see plate 7, Figs. A. and B), appar- 

 ently tending toward the condition noted in the so-called marantic 

 cases. 



Vascular Systei>i. — Changes in the heart are neither character- 

 istic nor constant. Fatty degeneration of the myocardium is, 

 however, not infrequently found, and in the acute terminal cases 

 parenchymatous alterations may be present. 



The arteries also occasionally show fatty degeneration of the 

 intima, as a rule, more pronounced in the larger trunks. Some 

 of the smaller visceral vessels show occasional interstitial increase 

 or arterio-capillary fibrosis ; and hyaline degeneration, particu- 

 larly in the vessels of the brain and cord, is not infrequent. 



Digestive Tract. — No changes except a general anaemia have 

 been observed and the clinical manifestations indicated normal 

 digestive function except in the later stages of the disease. 



Pancreas and Digestive Glands. — Xo lesions bearing on the 

 disease have been discovered. 



Liver. — More or less pronounced fatty degeneration is usually 

 seen, probablv largely the result of chronic congestion which is 

 almost invariablv present. Xot infrequently perivascular inter- 

 stitial hvperplasia, sometimes with round-celled infiltration and 

 active interstitial hepatitis, is found. 



Respiratory Tract. — Bronchitis is ordinarily present in the mid- 

 dle or later stages of the disease ; not infrequently it extends to 

 broncho-pneumonia, which is very often the immediate cause of 

 death in these cases. Chronic congestion of the lungs is also 

 verv common. These animals appear particularly prone to tuber- 

 cular infection, when the process is either most extensive in, or 



