Posterior Paralysis 



529 



hominy, middlings, and casein, made into a slop with an equal 

 weight of skim milk. A check group receiving added minerals 

 in the form of calcium carbonate and bone meal did not develop 

 the trouble. The alleviation of stiffness and the resumption of 

 growth was brought about in the group receiving no extra min- 

 erals either by the addition of the minerals in question, or, by a 

 daily addendum of 10 c.c. of cod liver oil. 



In the following winter eight out of thirteen pigs developed 

 the symptoms on the same ration, containing, however, yellow 

 corn meal in place of hominy, — even when calcium carbonate and 

 bone meal were included. Orange juice was added to the ration 

 of three of the affected pigs, which were obviously near death. 

 There was a marked temporary improvement followed in two 

 weeks by a decline and death. The addition of cod liver oil 

 produced only a slight improvement over a three weeks' period. 

 When the cod liver oil was replaced by 5 per cent, of chopped 

 alfalfa hay in the case of two of these pigs, permanent improve- 

 ment resulted. 



According to the symptoms of apparent paralysis, it was 

 thought that the lesions might be in the lumbar enlargement of 

 the spinal cord. Examination of the cord by the Nissl's method, 

 did not show any tissue changes. The principal and constant 

 lesions in the pigs fed as described in the preceding paragraph 

 were found in the bones and in the kidneys. Eight of the pigs 

 examined showed acute pneumonia. The bronchi of all of these 

 were infested with strongyhis paradoxus. The bone lesions were 

 most frequently seen in the ends of the femur. Here the 

 epiphyseal cartilage was thicker than normal and irregular. The 

 sub-epiphyseal bony trabecular were atrophied and gone in places, 

 with the marrow spaces filled with fibroblasts, newly formed blood 

 vessels, and hemorrhage, mostly under the epiphyseal cartilage. 

 As a result of this, the cartilage was loosened from the diaphysis 

 in some of the animals. The subchondral epiphyseal bone showed 

 similar changes, consisting of granulation tissue and hemorrhage 

 in place of normal bone. The zone of provisional calcification 

 was irregular, the articular cartilage was degenerated in places 

 and in other areas was invaded by blood vessels from the sub- 

 chondral bone. The epiphysis was affected for two-thirds of its 

 extent. These changes easily account for the spontaneous frac- 

 tures encountered in two of the pigs. At the junction of the 

 costal cartilage, there was a thickening in most of the cases ex- 



