September 25, 1896.] 



SCIENCE. 



459 



nature under tlie three headings — variation, 

 phylogeny and parallelism. 



The chapter on phylogeny brings together a 

 number of pertinent examples from the facts of 

 vertebrate paleontology, while variation and 

 parallelism are illustrated by both the Inverte- 

 brata and the Vertebrata. 



Under the subject of heredity over thirty 

 pages are devoted to the defense and proof of 

 the reality of transmission of acquired charac- 

 ters, and for this purpose are cited a goodly 

 array of evidences from both embryology and 

 paleontology. 



The particular memory theory of heredity, 

 of which the general principles were stated by 

 Sedgwick as early as 1863, and elaborated by 

 Cope in 1889, formulated by Herring in 1870 

 and named ' Mnemnogenesis' by Hyatt in 1893, 

 is adopted as best expressing the authors view. 

 The following passage presents a characteristic 

 definition of this factor of evolution. 



' ' It appears to me that we can more readily con- 

 ceive of the transmission of a resultant form of energy 

 of this kind to the germ-plasma than of material par- 

 ticles or gemmtiles. Such a theory is sustained by 

 the known cases of the influence of maternal impres- 

 sions on the growing foetus. Going into greater de- 

 tail, we may compare the building of the embryo to 

 the unfolding of a record or memory, which is stored 

 in the central nervous organism of the parent, and 

 impressed in greater or less part on the germ-plasma 

 during its construction, in the order in which it was 

 stored. This record may be supposed to be woven 

 into the texture of every organic cell, and to he de- 

 stroyed hy specialization in modified cells in propor- 

 tion as they are incapable of reproducing anything 

 hut themselves. The basis of memory is reasonably 

 supposed to he a molecular (or atomic) arrangement 

 from which can issue only a definite corresponding 

 mode of motion." (P. 451.) "The somatic cells 

 retain only the record or memory of their special func- 

 tion. On the other hand, the reproductive cells, 

 which most nearly resemble the independent unicel- 

 lular organisms, retain first the impressions received 

 during their primitive unicellular ancestral condition ; 

 and second, those which they have acquired through 

 the organism of which they have been and are only a 

 part." (P. 453.) 



To the question what are the primary factors 

 of organic evolution from a causative point 

 of view, the author's answer in brief seems to 

 be as follows : Bathmism an intrinsic energy 



of living matter ; Consciousness , a guiding in- 

 fluence, ' intrinsic in the evolving matter,' but 

 preceding organization ; molecular and molar 

 forces from without reacting upon bathmism 

 in the processes of Physiogenesis and Kineto- 

 genesis ; and the effects of these interactions 

 preserved and perpetuated in heredity through 

 the agency of memory in the process called 

 Mnemnogenesis. Viewed as a series of phe- 

 monena the author has summarized the par- 

 ticular form of doctrine defended in his book in 

 the following words : 



1. Variations appear in definite directions. 



2. Variations are caused by the interaction of the 

 organic being and its environment. 



3. Acquired variations may be inherited. 



4. Variations survive directly as they are adapted 

 to changing environments ( natural selection ) . 



5. Movements of the organism are caused or direc- 

 ted by sensation and other conscious states. 



6. Habitual movements are derived from conscious 

 experience. 



7. The rational mind is developed by experience, 

 through memory and classification (p, 14 ) . 



Most, if not all of the particular views of the 

 author found in this book have been more or 

 less fully elaborated in previous papers ; but in 

 their connected systematic form, combined with 

 the views of other workers to constitute a con- 

 sistent doctrine of evolution, we have in .' Pri- 

 mary factors ' a valuable text-book for teachers 

 and students. 



Whether they will be helped toward an intel- 

 lectual comprehension of the true factors of 

 evolution by this attempt to express them in 

 terms of those highest of all, most complex and 

 least understood of organic phenomena, con- 

 sciousness and memory, naay be seriously ques- 

 tioned. H. S. Williams. 



Yale University. 



The Manufacture of Explosives. By OscAR 

 GuTTMANN. 2 Vols., pp. 348 and 444 Ig, 8vo. 

 New York, Macmillan & Co. 1895. 

 As the sub-title of this book indicates, the 

 author has sought to produce a theoretical and 

 ]5ractical treatise on the history and the physi- 

 cal and chemical properties, as well as on the 

 methods of manufacture of explosive substances, 

 and he has followed for this purpose the plan 

 adopted in the excellent treatises on Gunpowder 



