from previous generations of domestic dogs. A precisely analogous reversal of the hairs is found on the under or extensor surfaces of the forelegs, matching with wonderful exactness the area of pressure of these on the ground, and anyone can see it who has a canine friend of the fox-terrier type. Long-haired dogs display it less neatly outlined. An instance such as this cannot be excluded from the evidence forthcoming because it is correlated with the useful “character” of lying in a certain attitude. Such a phenomenon, many similar to which will be seen later, had at any rate an origin _de novo_ at _some time_ in the ancestral stock, and in _some way_. To discover these is part of my business. The boldest neo-Darwinian will not claim that this arrangement of a dog’s hair arose by selectional processes within the germ either in the initial or completed stages. [34] My italics. Correlation. The term “correlation” is somewhat scornfully said by Weismann to be “unquestionably a fine word,” and it has indeed in biological writings a very varied set of meanings. I will not vex the reader with a reference to our old friend Mesopotamia, but mention what Dr. Vernon in _Variation in Animals and Plants_ says of the term, referring to the relation between stature and head-index in man: “Such a statement must vary according to the notion of the observer as to what does and what does not constitute correlation.”[35] The most approved and precise meaning of the loose term in question is that associated with the work of the biometricians, and a few examples from Dr. Vernon’s book will show how far this conception of correlation is removed from the literal application of Professor Thomson’s formula. Dr. Vernon treats of such phenomena as the correlation of the long heads of greyhounds with length of legs, contrasting them with the shortened heads and legs of bull-dogs. He describes also the correlation in man between the stature and length of forearm from elbow to tip of middle finger, correlated measurements of crabs, of external structures of prawns, the tufts of Polish fowls correlated with perforations in the skull, also certain constitutional peculiarities with colour of skin. These few cases are enough to give an idea of the more precise and fairer acceptation of the term, but while these form a useful subject for minute study it may be remarked that they agree also with Lamarckian factors as to their origin and development. They are much more in line with Darwin’s use of the word and are strangely reminiscent of the well-known example of the Irish elk with its great head and horns which was brought forward in favour of Lamarckism by Herbert Spencer. They breathe an atmosphere of physiology rather than anatomy, or function than form. [35] p. 74.