INFLAMMATION. 397 







at first grew rapidly, but soon diarrhoaa set in, they emaciated and became 

 rachitic. The bones became so soft that the animals walked on their femurs 

 and humeri, which were very much curved. The main cause of rachitis, 

 according to this author, is animal food, given too early. 



Or. Wegener * made experiments on fowls and calves, producing rachitic 

 changes by the administration of small doses of phosphorus, continued for 

 months. He found the epiphyseal cartilage considerably dissolved out, and 

 also in a high degree of hypergemia. 



The histology of rachitic bones has been studied by many excellent 

 observers, such as H. Meyer, R. Virchow, H. Miiller, A. Kolliker, C. Wedl, 

 Steudener, and others. H. Meyer t especially comes to the conclusion that : 

 (1) osteomalacia is osteoporosis; (2) rachitis originates from universal peri- 

 ostitis ; (3) osteomalacia and rachitis are the consequences of one and the 

 same disease. 



We know that, in the normal process of ossification, both car- 

 tilage and periosteum are reduced to a juvenile condition, giving 

 rise to medullary tissue. Simultaneously, also, new red blood- 

 corpuscles and blood-vessels are formed. In rickets, all this is 

 going on in a more rapid manner, but the new formation of bone 

 from the medullary tissue is very scanty or entirely absent. 



In sagittal sections of the epiphyseal ends of rachitic bones 

 we notice an intensely yellowish-red zone on a level with the 

 portions in which the formation of medullary tissue from carti- 

 lage is going on, and we see that this portion is considerably 

 thickened, constituting the characteristic rachitic swelling of the 

 shaft-bones. Under the microscope we find, at the level men- 

 tioned above, large cartilage corpuscles containing a far greater 

 amount of bioplasson than normal. The calcification of cartilage 

 is scanty and in irregular patches, or sometimes completely 

 wanting. The large, irregular, newly formed medullary spaces 

 abound in hollow, club-shaped formations the future capillaries 

 which contain numerous haematoblasts and red blood-corpus- 

 cles. At the peripheral portions of the epiphyseal cartilage a 

 new formation of vascularized cartilage, instead of bone, can be 

 traced, while the newly formed trabeculae of bone are scanty, 

 irregular in shape, holding large bone-corpuscles and territories 

 with distinct boundary lines. Similar features are observed at 

 the points of junction of hyaline cartilage and bone in rachitic 

 ribs. Here, too, the new formation of cartilage is proceeding 

 from medullary tissue on a large scale, mostly in groups, repre- 

 senting the territories. The cartilage is dissolved out, leaving a 



* Virchow'sArchiv, Bd.lvi. 



t "Zur Lehre von den Knochenkrankeiten." Henle u. Pfeiffer's Zeitschr., iii., 1853. 



