This article cannot be looked on as complete in any sense, yet the data have considerable value in conjunction with the experiments given in the other papers of the series. It is evident that more experiments are needed to determine the exact influence of the cooked parenchymatous organs and organ extracts on liver cell repair. Incomplete proteins, for example, gelatin, should be tested to ascertain if possible what repair can take place on such diets. The lipoids and allied substances may have a part in this reaction and the influence of thyroid and other ductless glands or extractives of these glands should be worked out. Some of this work we hope to carry out in the near future. From the experiments at hand it is clear that the liver will regenerate at maximum speed following a unit chloroform necrosis if the animal is fed a diet rich in carbohydrate, a