On the relation of the body length to the body weight and to the weight of the brain and of the spinal cord in the albino rat (mus norvegicus Var. albus)

I n a recent paper (Donaldson, ' 0 8 ) the relations of the body weight to the weight of the brain and of the spinal cord in the albino rat have been described.I n addition to the determination of the body weight it was stated in the paper just cited (pp.346-7) that measurements had also been made on the body length (trunk and head) of some of the rats, but to avoid confusion the discussion of this character and its relations was reserved for the present paper.The reasons for making a series of linear measurements on the albino rat were briefly the following:-1.To obtain a second general measure of the body growth of the albino rat in terms other than those of weight.2. To gather data by which to determine the body weight and body length ratio for the variety measured.This ratio is valuable because it gives a notion of the general shape of the animal and also enables us to state whether there are 'I'HE