This indication, if taken in the positive sense--as was sufficiently shown in considering the significance of the “mule” form or “hybrid-character”--we now know may be absolutely worthless, and in any unfamiliar case is very likely to be so. Mendel has proved that the inheritance from individuals of _identical ancestry_ may be entirely different: that from identical ancestry, without new variation, may be produced three kinds of individuals (in respect of each pair of characters), namely, individuals capable of transmitting one type, or another type, or both: moreover that the statistical relations of these three classes of individuals to each other will in a great number of cases be a definite one: and of all this he shows a complete account. Professor Weldon cannot deal with any part of this phenomenon. He does little more than allude to it in passing and point out exceptional cases. These he suggests a study of ancestry will explain. As a matter of fact a study of ancestry will give little guide--perhaps none--even as to the probability of the phenomenon of dominance of a character, none as to the probability of normal “purity” of germ-cells. Still less will it help to account for fluctuations in dominance, or irregularities in “purity.” _Ancestry and Dominance._ In a series of astonishing paragraphs (pp. 241–2) Professor Weldon rises by gradual steps, from the exceptional facts regarding occasional dominance of green colour in _Telephone_ to suggest that the _whole phenomenon of dominance may be attributable to ancestry_, and that in fact one character has no natural dominance over another, apart from what has been created by selection of ancestry. This piece of reasoning, one of the most remarkable examples of special pleading to be met with in scientific literature, must be read as a whole. I reproduce it entire, that the reader may appreciate this curious effort. The remarks between round parenthetical marks are Professor Weldon’s, those between crotchets are mine.