cular item, and in the single form in which it has come to hand, we proceed to use it in comparison with some foreign parallel or with some savage parallel. But that comparison must be imperfect unless we know that the example is in fact the most perfect survival of the original that is to be found. Its relationship to other examples of the same species must be carefully traced out, and the particular evidence which that relationship brings out must be taken into account. The work here indicated is a laborious one and a lengthy one, but, being necessary and being scientific, it is a work which I would urge the Society in every way to encourage, if not to actually commence undertaking it for our own country.
The second principle, which I think flows from the first, is what I would call the measurement of the survival. To some extent I indicated this also in my little book already referred to; but it is to Mr. Abercromby that we owe a clear pronouncement on the subject. "Though the word survival", says Mr. Abercromby, "strictly connotes the notion of uninterrupted continuity between its extreme terms it does not involve any exact notion of length. Survivals may therefore be of different lengths or ages. If a line AZ be taken to represent the earliest possible survival down to the present time, then FZ, SZ, VZ will represent shorter ones, the alphabetical distance of F S V and Z showing their relative distances from that point." These are weighty words, and they formulate a principle which, though existing in many of our minds, has not yet been actually set forth and expressed. I would, however, venture to make an amendment upon Mr. Abercromby's plan. I would use figures up to a hundred, instead of the alphabet; and then our measurer would assume somewhat the form of a barometer, the several stages being marked according to the circumstances of each country. So that Mr. Abercromby's suggestion may not fall idly by, I have ventured to construct, for the purpose of criticism, what we might call the British measurement of the survival,
