November 10, 1916] 



SCIENCE 



685 



swered, and by his resourcefulness in experi- 

 mental verification. 



The theory seems less satisfactory in its 

 application to the phenomena of gametic re- 

 production than to the processes of regenera- 

 tion. Pushed to its logical extreme in its 

 application to ontogenesis the process of in- 

 dividuation postulated by Child appears to be 

 one of complete epigenesis and the organiza- 

 tion which develops to be due exclusively to 

 external factors. In order to meet the in- 

 superable difficulties which would be raised 

 against a consistent theory of epigenesis, Dr. 

 Child assumes that as a result of the influence 

 of external conditions through many genera- 

 tions and through the inheritance of the ac- 

 quired modifications, reproductive cells or 

 cell-masses have come to possess " a funda- 

 mental reaction system " which constitutes a 

 basis of preformation and conditions their de- 

 velopment and their reaction to external 

 stimuli. In this way it is possible to under- 

 stand why under similar external conditions 

 the ontogenesis of different species varies so 

 greatly. Moreover, the " fundamental reac- 

 tion systems " may be further modified 

 through their intra-individual environment. 



In order to meet the difficulty of under- 

 standing how a " reaction system " involving 

 primarily only quantitative dynamic differ- 

 ences determines specific qualitative differ- 

 ences which appear in ontogeny, Dr. Child 

 is led to assume primary differences in the 

 specific constitution of the protoplasm of dif- 

 ferent eggs or cell-masses. But, since " sys- 

 tems" suggest spatial localization and the 

 " specific constitution of protoplasm " implies 

 chemical differentiation, does it not seem as 

 if the basis of individuality postulated by Dr. 

 Child is essentially like that assumed in the 

 hypotheses which Dr. Child repudiates? On 

 the whole, however, Dr. Child's hypothesis of 

 individuality appears to be the best supported 

 and the most consistent mechanistic hypoth- 

 esis which has been advanced. 



As the product of the mature thought of an 

 independent and resourceful investigator " In- 

 dividuality in Organisms " will take a perma- 

 nent place in biological literature. 



H. V. ISTeal 



PROCEEDINGS OF THE NATIONAL 

 ACADEMY OF SCIENCES 



The tenth number of Volume 2 of the Pro- 

 ceedings of the National Academy of Sciences 

 contains the following articles : 



Preliminary Results on the Color of Neb- 

 ula: F. H. Seares, Mount Wilson Solar Ob- 

 servatory, Carnegie Institution of Washing- 

 ton. Photographs of a Messier 51, 94, 99 show 

 that the nebular condensations have large 

 negative color indices. The knots of nebulos- 

 ity are bluer than the bluest of the neighbor- 

 ing stars. The spectral character of the out- 

 lying regions differs from that of the central 

 nucleus. In the case of the planetary nebula 

 E". G. C. 3242 no important differences of this 

 sort are revealed. 



The Action of Alkali in the Production of 

 Lipolytically Active Protein: ~K. George Falk, 

 Harriman Research Laboratory, Roosevelt 

 Hospital, New York. The author discusses: 

 Inactivation of the enzymes by acid, by 

 alkali, by alcohols, by acetone, by salts and by 

 heat; nature of the chemical changes involved 

 in the inactivations; and activation of proteins 

 by alkali. 



The Excretion of Acids by Roots: A. E. 

 Haas, Laboratory of Plant Physiology, Har- 

 vard University. The author finds that no 

 acid other than carbonic was excreted from the 

 roots of corn seedlings. Similar results were 

 obtained for wheat seedlings. 



Spectrographs Observations of Relative 

 Motions in the Planetary Nebula: W. W. 

 Campbell and J. H. Moore, Lick Observatory, 

 University of California. Further observa- 

 tions indicating the probability of the hypoth- 

 esis that the so-called ring nebula? are in real- 

 ity not ring forms, but ellipsoidal shells. 

 Tentative conclusions are also drawn as to the 

 probable masses of the nebula?. 



New Determinations of Permeability: S. C. 

 Brooks, Laboratory of Plant Physiology, 

 Harvard University. The determinations have 

 been made by a new independent method and 

 by improved older methods. The results agree 

 in showing that living protoplasms are nor- 

 mally permeable to the salts studied, but salts 

 of pure solutions may alter permeability, some 

 causing an increase of permeability while 



