According to what is perhaps the latest theory, that of M. Quinton, the temperature immediately below this, 44° _Centigrade_, remains always the best for living things, and those creatures are highest in the scale of life, and consequently the most developed, which have contrived means of keeping their internal heat at, or about, this level, despite the refrigeration of their surroundings. In their blood-heat M. Quinton therefore finds an absolute rule for fixing the relative rank of organic forms, and the date of their appearance; those whose blood is warmest being the most recently evolved. The results of this new system are sufficiently startling. Birds are to be classed as the highest and newest of all; while man, with the other _Primates_, has to take a much lower place, the ungulates, including the horse and donkey, and the carnivora, as dogs and cats, being his superiors. (_La Revue des Idées_, January 15, 1904, pp. 29 seq.) [90] To D. Mackintosh, February 28, 1882. [91] To Sir J. D. Hooker, March 29, 1863. [92] To V. Carus, November 21, 1866. [93] To D. Mackintosh, February 28, 1882. [94] _Riddle of the Universe_, p. 6. [95] _As regards Protoplasm_, p. 21. [96] _Encyclopaedia Britannica_, "Biology." [97] Printed in _Lay Sermons_. [98] _Nature_, June 5, 1902, p. 121. [99] _Id. ibid._ [100] _Op. cit._ p. 27. [101] _Presidential Address_, British Association, 1887. [102] _Les Emules de Darwin_, ii. 66. [103] _Op. cit._ ii. 63. [104] _Darwinism_, p. 474. [105] The other stages presenting similar difficulties are the 5th and 6th of Du Bois-Reymond's Enigmas, viz. the introduction of sensation or consciousness (animal life), and of rational thought and speech. [106] _Contemporary Review_, January, 1878, p. 298. [107] _Die sieben Welträthsel_, D. 82. [108] Professor Huxley, it must be remarked, speaks of Homer as a "half savage Greek" (_Lay Sermons_, p. 12), and intimates a mild wonder that such a being could share our feelings in presence of nature to so large an extent as his poems testify. This is undoubtedly a fine example of the good conceit of ourselves which the pursuit of science is rather apt to produce. [109] _Darwinism_, p. 475. [110] _Descent of Man_, c. ii. [111] _Ibid._ 54. [112] In his paper read before the British Association at Oxford in 1847. [113] _Lessons from Nature_, p. 89. [114] See Mivart, _Origin of Human Reason_, p. 166. [115] See Louis Arnould, _Une âme en prison_, and article "An imprisoned Soul," by the Ctesse. de Courson, _The Month_, January, 1902, p. 82. [116] _Descent of Man_, i. 57. [117] i.e. ape-like. [118] Quoted by Romanes, _Mental Evolution in Man_. [119] _Ibid._, p. 371. [120] _Origin of Human Reason_, p. 385. [121] _Op. cit._ p. 379. [122] _Riddle of the Universe_, p. 46.