ON APwCn^STHETISM. 409 



served. For these I refer to papers by Messrs. Alpheus Hyatt, 

 J. A. Ryder and myself : by Prof. Hyatt ..." Upon the Effects 

 of Gravity on the Forms of Shells and Animals ; " * Mr. Ryder 

 *'0n the Mechanical Genesis of Tooth Forms ;" f and '*0n the 

 Laws of Digital Reduction ;" ]; by myself '' On the Origin of the 

 Specialized Teeth of the Oarnivora ; " * " On the Origin of the 

 Foot Structures of the Ungulates ; " || "On the Effect of Impacts 

 and Strains on the Feet of Mammalia." ^ Now demonstration of 

 the meclianical effects of the application of force to matter can 

 only be obtained by observation of the process, and this can not 

 be seen, of course, by the observation of fossils. The relation of 

 the observed facts to the hypothesis is, however, shown by the 

 above papers to be so precise that it only needs observation on the 

 production of similar changes by similar causes in living types to 

 give us a demonstration by induction, which will satisfy most 

 minds. That such facts have been observed among the lower ani- 

 mals is well known. The change of form of animals without 

 hard parts, in adaptation to their environment, is an every-day 

 occurrence. 



That these views are now shared by many naturalists is be- 

 coming every day more evident. Prof. E. Dubois-Raymond ^ has 

 recently delivered a lecture before the physicians of the German 

 army, on exercise or use, in which he makes some important 

 admissions. We give the following extract : " We should be, 

 therefore, free to admit, with some appearance of reason, that the 

 vigor of the muscles of wings and of digging feet ; the thick 

 epidermis of the palm of the hand and of the sole of the foot ; 

 the callosities of the tail and of the ischia of some monkeys ; the 

 processes of bones for the insertion of muscles ; are the conse- 

 quences of nutritive and formative excitation, transmitted by 

 heredity." In this position Prof. Raymond is in strict accord 

 with the Lamarckian school of evolutionists. But Prof. Raymond 

 still clings to the obscurities of the Darwinians, though Darwin 

 himself is not responsible for them, in the following sentences : 

 " It is necessary to admit, along with development by use, develop- 



* "Proceeds. Amer. Assoc. Adv. Science," 1880, p. 527. 



f " Proceedings Academy Philadelphia," 1878, p. 45 ; 1879, 47. 

 X Loe. cit.^ 1877, October. 



# " American Naturalist," March, 1879, p. 171. 



II Loc. cit, April, 1881, p. 269. ^ Loc. cit, July, 1881, p. 542. 



l "Revue Scientifique," Paris, Jan. 28, 1882. 



