282 ASCORBIC ACID 



(framework marrow) of German authors." Eventually resorption of bone 

 matrix with marked changes in the epiphyseal cartilage occurs. The cells 

 of the periosteum cease to form bone, and the attachment of the trabeculae 

 with the epiphyseal cartilage becomes weak, with a resulting tendency to 

 fractures in the epiphysis and diaphysis. Fractures of the calcified matrix 

 material result in a region of complete degeneration, the Triimmerfeld zone. 

 Continued proliferation of osteoblasts of the periosteum causes the perios- 

 teum to become separated from the Iwne cortex. The osteoblasts increase 

 in number, but no intercellular material (osteoid) is formed. Resorption of 

 bone salts occurs, resulting in rarification of the bones, a change which 

 Meyer^^ found to occur over the entire skeleton with all the large bones 

 becoming smoother and appearing somewhat glassy. Although absorption 

 in the bones was marked, he rarely found osteoclasts present. Harman et 

 01}^"^ found that guinea pigs after 4 weeks on an ascorbic acid-deficient diet 

 showed resorption of the jaw bone at the bases of the molars and along the 

 edge of the alveolar area. This was true for animals ranging in age from 

 20 days to 3 years. Robertson ^^ found that significant losses of collagen from 

 bones and teeth occur in scurvy. MacLean et al.^^ found that in acute de- 

 ficiency of vitamin C in guinea pigs no characteristic histological changes 

 occur in tissues other than in bones and teeth. It would thus seem probable 

 that the changes in other tissues observed by various investigators were a 

 consequence of a less acute deficiency of the vitamin, or possibly in some 

 instances a deficiency of essential factors other than vitamin C. As to de- 

 generative changes in the cartilage cells Meyer^^ observed that in vitamin 

 C deficiency the cytoplasm may become vacuolated and rarefied and that 

 later degenerative changes may occur in the nuclei and finally in the matrix 

 resulting in complete loss of substance. Hojer^ noted a collagen atrophy in 

 the cartilage which was particularly marked in and near the columns of the 

 proliferating zone. Some of the other workers have not found definite 

 changes in cartilage, possibly because under their experimental conditions 

 the scurvy progressed rapidly, allowing insufficient time for the changes to 

 develop. 



c. Teeth 



Growth of the guinea pig's incisors is very rapid under conditions of good 

 nutrition. A growth of 2 mm. per week occurs, in contrast to a few milli- 

 meters per year for humans.'"^ Zilva and Wells^ showed that pathological 

 changes in the odontoblasts and dentine occur in scurvy. Hojer^ made a 

 very important contribution in which he showed that the growth and ar- 

 rangement of the odontoblasts is directly related to the vitamin C intake. 



102 M. T. Ilarman, M. M. Kramer, and H. D. Kirgis, J. Nutriiion 15, 277 (1938). 

 1" P. E. Boyle, J. Dental Research 14, 172 (1934). 



