458 



SCIENCE. 



[N. S. Vol. IV, No. 91. 



In elaborating this theory energies are distin- 

 guished into two classes. The first class in- 

 cludes those which tend away from the pheno- 

 mena of life, ' catagenetic, ' some of which are 

 exclusively organic, myism and neurism ; while 

 others are both organic and inorganic, as gravi- 

 tation, cohesion, chemism and radiant energy. 

 The other class, 'anagenetic,' includes only 

 those which tend toward the phenomena of life. 

 The particular form of this ' ' energy, which is 

 displayed by the plant in the elaboration of liv- 

 ing from non-living matter is called antichem- 

 ism " (p. 483), the other growth- energies are 

 called ' bathmisms. ' Bathmisms are further 

 subdivided according as they are influenced by 

 the interference of energies which are derived 

 from sources external to the germ plasma. 



To the 'simple growth force,' which is di- 

 rectly inherited without interference of other 

 forces is given the name ' emphytism,' to distin- 

 guish it from the modified forms of growth force 

 called ' grade growth force,' to which the name 

 bathmism is strictly applied. As the author re- 

 marks, ' ' pure emphytism can only be observed 

 in the embryos of sexless or parthenogenetic 

 origin, and in the repair of tissues." (P. 485.) 



We thus are left with bathmism as the mode 

 of energy, and bathmogenesis as the process by 

 which the phenomena of evolution are accom- 

 plished. 



As the present writer understands the author, 

 his idea is that it is through the interaction or 

 interference between energies from without the 

 germ, though not necessarily outside the soma, 

 and the particular bathmic energy of the germ 

 itself which determines the specific morphologi- 

 cal characters of each organism. 



Under Part II., 'The Causes of Variation,' 

 the author discusses the ways by which these 

 interferences are accomplished. These external 

 influences are found to be of two classes, physi- 

 cochemical (molecular) and mechanical (molar). 

 The class of evolutional phenomena "resulting 

 from interference between the molecular ener- 

 gies and bathmism are given the name ' Physio- 

 genesis,' those resulting from interference be- 

 tween molar energy and bathmism are called 

 ' Kinetogenesis.' 



In the chapter on physiogenesis are found il- 

 lustrations quoted from various authors of cases 



of physiogenesis, as the conversion of Artemia 

 into Branchinecta ; the production of colors in 

 Lepidopterous pupse ; the effect of feeding on 

 color in birds ; the blindness of cave-animals, 

 etc. 



In illustration of the law of kinetogenesis the 

 studies made by Dall on the origin of the plaits 

 in the columella of the Gastropods, and by Jack- 

 son on the mechanical origin of characters in 

 the Lamellibranchs, are cited from the Inver- 

 tebrata. 



Kinetogenesis in the Vertebrata is elaborately 

 illustrated by numerous references to the work 

 of other authors and his own researches, on the 

 effects of 'impact' and ' strains,' in modifying 

 osseou.s tissue, the form of limb articulations and 

 vertebral center, on the increase of size through 

 use, the size and number of digits and the modi- 

 fication of the shape of horns, etc. But per- 

 haps the most interesting and satisfactory 

 application of the law is seen in the explana- 

 tion of the mechanical origin of dental types, in 

 which the paleontological evidence has proven 

 of the greatest value and has given powerful 

 confirmation to the general neo-Lamarckian 

 theories, which find their strongest supporters 

 among the vertebrate paleontologists of the 

 United States. 



The effects of disuse are also exemplified in 

 the cases of atrophy, abortion and modification 

 of limb-bones in mammalia. 



This ' use and disuse ' of Lamarck, under the 

 modes of physiogenesis and kinetogenesis, are 

 the processes through which variation of form 

 and structure are attained. 



Natural selection is recognized as a means 

 and mode of the accentuation and preservation 

 of modifications found to be useful ; but the 

 author is particular to note that natural selec- 

 tion does not induce variability, but simply pre- 

 serves such variations as arise and are beneficial 

 to the being under its conditions of life, quoting 

 from Darwin in support of this view (p. 4). 

 Thus he takes exception to the extreme Neo- 

 Darwinian, or Wallacean doctrine, as it is called 

 by Romanes, in so far as to deny that species 

 and the distinctive characters of every species 

 are due to natural selection. 



In Part 1st the common phenomena of evo- 

 lution are expounded by examples of a vividi^ 



