"Consequently, it may be said that the extent of the problem, as well as the importance of its solution, far exceeds the limits of penitentiary work and the interest, which is however by no means inconsiderable, that penal action has excited amongst various nations. These are the motives for giving to the labours of M. Bertillon and to their practical utilisation the publicity they merit." These full and clear remarks seem even more applicable to the method of finger prints than to that of anthropometry. CHAPTER XI HEREDITY Some of those who have written on finger marks affirm that they are transmissible by descent, others assert the direct contrary, but no inquiry hitherto appears to justify a definite conclusion. Chapter VIII. shows a close correlation to exist between the patterns on the several fingers of the same person. Hence we are justified in assuming that the patterns are partly dependent on constitutional causes, in which case it would indeed be strange if the general law of heredity failed in this particular case. After examining many prints, the frequency with which some peculiar pattern was found to characterise members of the same family convinced me of the reality of an hereditary tendency. The question was how to submit the belief to numerical tests; particular kinships had to be selected, and methods of discussion devised. It must here be borne in mind that "Heredity" implies more than its original meaning of a relationship between parent and child. It includes that which connects children of the same parents, and which I have shown (_Natural Inheritance_) to be just twice as close in the case of stature as that which connects a child and either of its two parents. Moreover, the closeness of the fraternal and the filial relations are to a great extent interdependent, for in any population whose faculties remain _statistically_ the same during successive generations, it has been shown that a simple algebraical equation must exist, that connects together the three elements of Filial Relation, Fraternal Relation, and Regression, by which a knowledge of any two of them determines the value of the third. So far as Regression may be treated as being constant in value, the Filial and the Fraternal relations become reciprocally connected. It is not possible briefly to give an adequate explanation of all this now, or to show how strictly observations were found to confirm the theory; this has been fully done in _Natural Inheritance_, and the conclusions will here be assumed.