In introducing his own explanation of things, Mr. Bennett affirms that ‘resemblances, and resemblances of the most wonderful and perfect kind’ in the vegetable kingdom, ‘are in no sense mimetic or protective.’ This may be so, but it can hardly be said to be proved. When he speaks of ‘man’s reason’ having ‘assisted him so to modify his body as to adapt himself to the circumstances with which he is surrounded,’ and suggests that the instinct of animals may have assisted them also to modify their bodies by slow and gradual degrees to the same purpose, it is difficult to imagine the process intended, and still more difficult to see how ‘the slow and gradual degrees’ will escape the rigid test of mathematical calculation which Mr. Bennett has elsewhere applied; for if the steps are great, they ought not to be permanent; and if small, they ought not to be useful. A theory which makes it possible for a bee to ‘modify its proboscis’ by instinct, or for a man to treat his nose in the same manner by reason, seems harder of digestion than the Darwinian. Torquay, Nov. 12, 1870. THE GENESIS OF SPECIES. A review in ‘Nature,’ by Mr. A. W. Bennett, of Mr. Mivart’s ‘Genesis of Species,’ contains the following passage:-- ‘It behoves, therefore, every Darwinian to satisfy himself that either Mr. Mivart’s premisses or his line of argument is unsound. ‘The objections brought forward by the author are summed up as follows:--(1) That Natural Selection is incompetent to account for the incipient stages of useful structures. (2) That it does not harmonize with the coexistence of closely similar structures of diverse origin. (3) That there are grounds for thinking that specific differences may be developed suddenly instead of gradually. (4) That the opinion that species have definite though different limits to their variability is still tenable. (5) That certain fossil transitional forms are absent which might have been expected to be present. (6) That some facts of geological distribution supplement other difficulties. (7) That the objection drawn from the physiological difference between “species” and “races” still exists unrefuted. (8) That there are many remarkable phenomena in organic forms upon which Natural Selection throws no light whatever, but the explanations of which, if they could be attained, might throw light upon specific origination. ‘If these objections are not new, they are at least sustained by new arguments. They are evidently of very unequal value. The third is very difficult of proof or disproof. The fifth may be true in our present state of knowledge, but would be very unsafe by itself as the basis of an argument. The first, second, and eighth are of greatest value, and are those which Mr. Mivart has most closely worked out[68].’