490 NATURAL SCIENCE. s^,,,,_ 



manner ; and few will doubt that the human frame is still undergoing 

 marked evolution. 



In the first place, the Professor well points out that, physically 

 speaking, man is far from being a pre-eminent creature : — 



" From the typical mammalian standpoint, man is a degenerate 

 animal ; his senses are inferior in acuteness ; his upright position, 

 while giving him a superior aspect, entails many disadvantages, as 

 recently enumerated by Clevenger, for the body is not fully adapted 

 to it ; his feet are not superior to those of many Lower Eocene planti- 

 grades ; his teeth are mechanically far inferior to those of the 

 domestic cat. In fact, if an unbiased comparative anatomist should 

 reach this planet from Mars he could only pass favourable comment 

 upon the perfection of the hand and the massive brain ! Holding 

 these trumps, man has been and now is discarding many useful 

 structures. I refer especially to civilised man, who is more prodigal 

 with his inheritance than the savage. By virtue of the hand and 

 brain he is, nevertheless, the best adapted and most cosmopolitan 

 vertebrate." 



Professor Osborn's review must be carefully read in detail to be 

 appreciated. The lower jaw of man, we are told, is distinctly 

 becoming reduced in size ; the " wisdom tooth " is disappearing, and 

 the life of civilisation is tending to a degeneracy of all the teeth. 

 There is a frequent reduction in the number of the ribs, resulting in a 

 shortening of the chest, probably correlated with man's upright 

 position. The arm is becoming more adapted to freedom of motion. 

 Owing to our present habits of walking, the great toe of the foot is 

 increasing, while the little toe is diminishing ; and in many human 

 skeletons the two end-joints of the little toe are fused together. In 

 many of the muscles, too, there is evidence of change ; and there is 

 no doubt that the man of the near future will differ much in his frame 

 from the civilised man of the present. 



The Ear. 



Another welcome contribution reaches us from America in the 

 form of an elaborate memoir on the organ of hearing in vertebrate 

 animals (H. Ayers, Joiirn. Movphologv, vol. vi., pp. 1-360, pis. i.-xii.). 

 The subject is treated from the point of view both of Comparative 

 Anatomy and Embryology ; and if Dr. Ayers' results are confirmed, 

 they will make an important advance in our knowledge of the meaning 

 of the various parts of the ear. 



So many new features are discussed, that it is impossible here to 

 indicate more than the principal outcome of the investigation. It is 

 now generally admitted that the ear originates in the lowest verte- 

 brates by a modification of the superficial nervous slime-canal system, 

 which gives rise to the conspicuous and familiar " lateral line " in 

 fishes. Dr. Ayers, on the present occasion, elaborates this idea. 

 It is well-demonstrated that the ear is supplied by the same nerves 

 that are connected with the superficial sense-organs of the "lateral 



