90 



SCIENCE. 



[N. S. Vol. VIII. No. 186. 



guises : (1) as a material bearer or vehicle 

 of the qualities ; (2) as a quasi-psychical 

 principle. The majority of biologists are 

 advocates of the former view, among them 

 Darwin, Spencer, Haeckel, Nageli, DeVries, 

 Wiesner, Weismann ; the latter view has 

 had numerous adherents from Bruno to 

 Bunge, among tliem Stahl, Jaeger, Bunge 

 and Hartmann. 



With remarkable insight, the author 

 criticises the theories of DeVries, Spencer, 

 "Weismann and ISTageli. The gist of this 

 criticism can be given here in only a few 

 fragmentary extracts. As to DeVries' theory 

 of Pangenesis he says, after giving DeVries' 

 point of view by various quotations from his 

 work: "It seems fairly evident that we 

 have to do with a metaphysical question 

 alone, in all these quotations, just the ques- 

 tion of identity in difference, of substance 

 and quality. The pangenes are anthro- 

 pomorphic agents, each one of which is a 

 material vehicle of a special quality. They 

 are anthromorphic because they are purely 

 self-determining and not passive, and be- 

 cause they know the right and do it. They 

 become functional when it is time for them to 

 do so ; they slip out of the nucleus ivhen they 

 are needed outside ; they go through the 

 cytoplasm to that part of the cell ivhlch re- 

 quires their quality." 



An account of Spencer's theory of Physio- 

 logical Units is then given and their contra- 

 dictory qualities are pointed out. " The 

 agents (units) are now similar to one an- 

 other, and again dissimilar ; they are now 

 merely constitutive and again directing. 

 The units are different when considered in 

 relation to the differences of the body, but 

 they are identical when considered in rela- 

 tion to the ideal identity of these differ- 

 ences. When a distinction is thus substi- 

 tuted for a vague self-contradiction the 

 units themselves present that problem of 

 the organism for the satisfaction of which 

 they were invented. They have the two 



aspects of identity and difference, and can 

 no longer be the identity for the given dif- 

 ferences of the body, so that they become 

 useless." 



Weismann's theory of the Germplasm is 

 then briefly sketched, and in conclusion the 

 author says : " Let us compare the deter- 

 minant to an organism. Like the organism, 

 the determinant can retain its proper form 

 and functions and is the same determinant 

 through all changes. It is fed ; it repro- 

 duces itself. It is not homogeneous, but 

 contains many ordered differences, and in 

 virtue of its qualities it does its work. Now 

 all its qualities are surely not the mere re- 

 sult of one another, for if they were it 

 would not retain its identity through all the 

 differences of its life any more than the 

 organism would do if cells were condi- 

 tioned by cells and stages by stages. You, 

 therefore, need another system of determi- 

 nants to control the determinants of Weis- 

 mann as soon as anything is known about 

 these, and to be the vehicles of their quali- 

 ties ; and you must then examine that new 

 system in order to see whether or no you 

 need yet another." 



Nageli's theory of Idioplasm is next con- 

 sidered, and it is shown that Nageli regards 

 the idioplasm as mere difference at one 

 time and as mere identity at another, and 

 finally that he considers it a quasi- psychical 

 principle which brings forth suitable quali- 

 ties at the appropriate time. Nageli himself 

 draws an analogy between the idioplasm 

 and a pianist, and in this analogy the author 

 finds a satisfactory summary of Nageli's 

 theory and a sufficient condemnation of it. 

 " The sounds answer to the manifold differ- 

 ences of appearance ; the keys to the idio- 

 plasm as mere differences ; the pianist to 

 the idioplasm as abstract identity ; and, 

 lastly, the score to the ideal unity in multi- 

 plicity. ISTow the analogy differs from the 

 known body in one respect, that it inserts 

 between the phenomenal differences and the 



