PROBLEMS OF BIOLOGY 321 



Very few have tried, and one or two (I know) have tried 

 and not succeeded, to trace the action and the effects of 

 surface-tension in the case of a highly complicated, multi- 

 segmented egg. But it is not surprising if the difficulties 

 which such a case presents appear to be formidable. Even 

 the conformation of the interior of a soap-froth, though 

 absolutely conditioned by surface-tension, presents great 

 difficulties, and it was only in the last years of Lord Kelvin's 

 life that he showed all previous workers to have been in 

 error regarding the form of the interior cells. 



But what, for us, does all this amount to ? It at least 

 suggests the possibility of so far supporting the observed 

 facts of organic form on mathematical principles, as to bring 

 morphology within or very near to Kant's demand that a 

 true natural science should be justified by its relation to 

 mathematics. 1 But if we were to carry these principles 

 further and to succeed in proving them applicable in detail, 

 even to the showing that the manifold segmentation of the 

 egg was but an exquisite froth, would it wholly revolutionise 

 our biological ideas ? It would greatly modify some of them, 

 and some of the most cherished ideas of the majority of 

 embryologists ; but I think that the way is already paved 

 for some such modification. When Loeb and others have 

 shown us that half, or even a small portion of an egg, or a 

 single one of its many blastospheres, can give rise to an entire 

 embryo, and that in some cases any part of the ovum can 

 originate any part of the organism, surely our eyes are turned 

 to the energies inherent in the matter of the egg (not to speak 

 of a presiding entelechy), and away from its original formal 

 operations of division. Sedgwick has told us for many years 



1 ' Ich behaupte aber dass in jeder besonderen Naturlehre nur so viel eigenttiche 

 Wissenschaft angetroffen werden konne, als darin Mathematik anzutreffen ist.' Kant, 

 in Preface to Metapfiys. Anfangsgrunde der Natunvissenschaft (Werke, ed. Hartenstein, 

 voL iv. p. 360). 



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