In these days of progress, when the alleged origin of the human race from a transmuted gorilla is canvassed as a demonstrable and demonstrated theory by many geologists and zoologists, and the pens of various distinguished writers are occupied to prove the absolute identity of man's physiological and psychological nature with that of the beasts of the field, it behoves the candid student of palæontology to inquire what are the fossil members of the Order of Mammalia immediately beneath man—the Quadrumana, and whether they are such individuals as might fulfil the hypothetical condition of being his ancestors, under any of the “derivative” theories propounded by Darwin or Lamarck.

In venturing upon this field of error, doubt, and confusion, I wish dispassionately to endeavour to divest myself of any adherence to any prevailing doctrine. Imbued strongly with the conviction of the unity of type of all animals, and with the probability of their common origin by secondary law, yet I advocate no theory which derives mankind from any known recent or fossil species of animal. Convinced of the distinctive peculiarities of the human brain, characters not satisfactorily demonstrated in any animal, yet I do not shut my eyes to the analogy which sometimes exists between the structures in the lowest men and the highest apes.