198 Chalmers Watson, 



dingly some of the later papers will be from the pens of observers 

 who have made an independent investigation of the subject on which 

 thej write. By this independent, yet correlated research, it is hoped 

 that a more complete examination of the tissues may be effected so 

 that we may be able at a later date to summarise the results as a 

 whole, and apportion due significance to the facts observed. 



The diets employed were five in number, — rice boiled in water, 

 oatmeal-porridge made with skim-milk and water, uncooked horse-flesh, 

 uncooked ox-flesh, and a control diet of bread soaked in skim-milk. 

 The chemical composition and heat values of these foods were deter- 

 mined by Dr. Andrew Hunter, and are given in detail in the former 

 paper, along with the results on weight and growth of the animals. 

 The present communication deals with the influence of a meat diet — 

 horse-flesh and ox-flesh — on the kidneys. Four series of obser- 

 vations were made as follows: 



I. On adult rats (7) fed on a horse-flesh diet for five months. 

 Thirteen controls were employed, seven being porridge-fed and six 

 bread-and-niilk-fed subjects. 



II. On young animals (8) the diet (horse-flesh or ox-flesh) being 

 begun either when the animals were weaned, or at the age of two 

 to three months. 



III. On castrated female rats (5) aet. approximately six months, 

 fed on a horse-flesh diet for four or five months. The controls were 

 eight in number, five being rice-fed and three porridge-fed animals. 



IV. On the second generation of meat-fed animals (horse-flesh 

 and ox-flesh). This series comprises thirty-two animals of ages 

 varying from twelve days to three months; it includes thirteen rats 

 which liad not been weaned. 



The special points to which attention was directed were (a) the 

 weight of the kidneys, and (h) their minute structure. 



a) The iveight of the Tcidneys. 



The weights are given in the form of tables. Each table records 

 the number of animals on the meat, and on the control diets, the 

 total weight of the animals at death, their maximum weight during 

 life, the total weight of the kidneys, and the percentage weight of 



