2 g8 inanition and malnutrition 



Lefholz ('23) found that the thymus, spleen and cervical lymph glands of 

 kittens showed no consistent response to dietary variations in the amounts of 

 fat, sugar and protein, although the tonsils and lymphoid structures of the 

 alimentary canal generally were markedly affected. 



In human rickets, Seibold (1827) noted: "Die Glandula Thymus und das 

 Mediastinum fand man meistens mit einzelnen Verhartungen." 



In 14 non-rachitic infants, du Castel ('08) found the thymus weight 

 above 8 g. (which was considered normal) in only 1, the average being 4.50 g. 

 But in 13 rachitic infants below 3 years of age, the thymus exceeded 8 g. 

 in 8 cases, the maximum being 15 g. and the average 9.42 g. "On 

 peu done conclure que dans la majeure partie des cas le thymus rachitique est 

 hypertrophic; l'augmentation du poids de l'organe est due a la proliferation du 

 tissu lymphoide; on trouve assez souvent des myelocytes en grande nombre; 

 les corpuscles de Hassall sont egalement plus nombreux que dans les thymus 

 non rachitique; enfin, le plus souvent, on n'y constate plus la sclerose, si fre- 

 quente chez ces derniers." It may be noted, however, that du Castel's thymus 

 weights are all actually subnormal (c/. Fig. 79) ; whether the thymus is larger 

 than would be expected in these cases, according to the general nutrition of 

 the body, is uncertain on account of the lack of data concerning body weight, etc. 



Sweet ('21) advanced the theory that rickets may be due to a deficient 

 secretion of the thymus; but this fails to account for the apparent antagonism 

 between rickets and starvation, which has repeatedly been noted in man and 

 animals, in spite of the profound atrophy of the thymus during starvation. 



Marfan ('22) confirms du Castel's claim that the thymus is enlarged in 

 human rickets, accompanying a general hypertrophy of the lymphoid organs 

 ("polyadenie"). 



In experimental rickets in rats, Shipley, Park, McCollum and Simmonds 

 ('21) found the thymus atrophic (no weights given) in animals on diets deficient 

 in fat soluble A, with or without deficiency also in phosphorus. A similar 

 condition was mentioned by McCollum, Simmonds, Shipley and Park ('21) 

 in rats on low calcium diets, with "undersized" bodies. 



From a study of the weights of the thymus in an extensive series of albino 

 rats, Jackson and Carleton ('23) found that the thymus averages slightly above 

 Donaldson's norm in the "normal control" group, but shows a progressive 

 decrease in weight in the test groups, reaching 70 per cent below normal in the 

 severely rachitic group (Table n). The weight-length ratio of the body was 

 nearly normal, but nearly all of the test rats were subnormal in weight according 

 to age, indicating a retardation in growth. This would tend to depress the 

 thymus weight, irrespective of any specific effect of the rickets. 



Several observations are available upon the thymus in beriberi (vitamin 

 B deficiency). Andrews ('12) in 18 necropsies of infantile beriberi found only 

 slight apparent changes in the thymus, aside from congestion. 



In animal experiments, however, a profound atrophy of the thymus in beri- 

 beri or polyneuritis was found by Funk and Douglas ('14) in pigeons; by Wil- 

 liams and Crowell ('15) in pigeons and chickens; by Douglas ('15) in pigeons; 

 by Drummond ('16) in chickens; by McCarrison ('19, '19a, '19b, '19c, '19c, 



