Being the Conclusion of the Fullerian Course of Lectures on Physiology, for 1859

In a Report to the British Association for the Advancement of Science, On the Extinct Mammals of Australia, published in the Volume of Reports for 1844, evidence is adduced in proof of the law, that with extinct as with existing mammalia particular forms were assigned to particular provinces, and that the same forms were restricted to the same provinces at a former geological period as they are at the present day. That period, however, was the more recent tertiary one.

In carrying back the retrospective comparison of existing and extinct mammals to those of the eocene and oolitic strata, in relation to their local distribution, we obtain indications of extensive changes in the relative position of sea and land during those epochs, through the degree of incongruity between the generic forms of the mammalia which then existed in Europe, and any that actually exist on the great natural continent of which Europe now forms part. It would seem, indeed, that the further we penetrate into time for the recovery of extinct mammalia, the further we must go into space to find their existing analogues. To match the eocene palseotheres and lophiodons we must bring tapirs from Sumatra or South America; and we must travel to the antipodes for myrmecobians, the nearest living analogue to the amphitheres and spalacotheres of our oolitic strata.