224 



SCIENTIFIC THOUGHT. 



semblance 1 of an explanation of organic structures and 

 forms, they have in reality done as little as Boscovich's 

 centres of force and curves of attraction and repulsion 

 in mathematical physics to establish a firm basis for 

 actual research ; for nowhere have they been capable of 

 exact determination such as has been applied to the 

 angles and figures of crystals. 



Simultaneously with the science of crystallography 



there came into being the science of minerals on a 



22. larger scale of study, through actual observation in 



on a large 'definite localities of the formation and stratification 



scale. 



of rocks ; of the traces of the influence of the great 



arrangements of Schimper, became 

 known under the term "Morph- 

 ologic ve'ge'tale," through Auguste 

 de Saint Hilaire in his ' Le9ons de 

 Botanique' (1840). To the spiral 

 theory, although strongly opposed 

 in course of time by Wilhelm Hof- 

 meister, one of the founders of the 

 genetic conception of plant life, 

 Sachs, the historian of botany, 

 nevertheless assigns an important 

 historical influence, " as through 

 Schimper's theory the morphologic- 

 ally so important relative position 

 of the plant organs was for the first 

 time placed in the foreground of 

 morphology" (loc. cit., p. 180). See, 

 however, on this subject the paper 

 by A. H. Church on " Phyllotaxis " 

 in vol. i. p. 49 of ' The New 

 Phytologist,' 1902. 



1 The early propounders of the 

 cellular theory of organic structures 

 adopted the view that cells were 

 formed in a surrounding liquid in 

 the manner of crystals in a mother- 

 liquor. When it was established 

 that organic structures grow by 

 intussusception, not by juxtaposition 

 and accretion, like crystals, and that 

 cells multiply by division, the dis- 

 coveries of Graham, who divided 



bodies into crystalloids and colloids, 

 were utilised for the purpose of 

 explaining or illustrating organic 

 processes. On this distinction is 

 based the celebrated " micellar 

 theory " of Nageli, who, in his 

 ' Mechanisch-physiologische Theorie 

 der Abstammungslehre ' (Miinchen 

 und Leipzig, 1884), works out a 

 complete mechanical doctrine of the 

 constitution and formation of or- 

 ganic structures. The ideas con- 

 tained in this elaborate treatise 

 have been much used in Germany 

 by various writers, but mostly only 

 as convenient illustrations. See 

 0. Hertwig, 'The Cell' (transl. by 

 Campbell, 1895), p. 58, &c. The 

 micellar theory does not seem to 

 have found much favour in France 

 or in this country, where a general 

 opinion prevails which is probably 

 best represented in the words 

 of Claude Bernard : " Les phe"no- 

 nienes physico-chimiques des etres 

 vivants, quoique soumis aux lois 

 de la physique et de la chimie 

 ge'ne'rales, ont leurs conditions par- 

 ticulieres qui ne sont re'alise'es que la, 

 et dont la chimie pure ne peut offrir 

 qu'uneimageplusou moinsinexacte" 

 (' Phen. delaVie,' &c., vol. ii. p. 487). 



