N works on the evolution of plank-built boats attention has never been directed sufficiently to the technique of the methods followed in their construction. The universal habit has been to take the vessels as they are in their completed state and to apply morphological methods to their study from this limited aspect; precisely as the oldfashioned conchologist studied and classified his shells by outward form without regard to the soft parts—the essential criteria, as we now know. It is true nevertheless that in respect both of mollusca and boats, the study of the outward form has led, generally, to an approximation to the truth, but conclusions so reached are not to be accepted as correct without correlated verification dependent upon study of the kernel within the husk. Thus it is that nearly the same conclusions to which I come in this paper, have already been suggested tentatively by Brindley; but, owing to the fact that he did not utilize the internal evidence now brought forward, his suggestions were controversial hypotheses which he could not prove conclusively; nor was he able to state definitely whether the divergent forms noted were reached by means of diffusion and local variation, or whether they arose through independent invention, or by a combination of the two factors.