AS REGARDS PROTOPLASM, ETC. 33 



literally ab ovo brain-cells only generate brain-cells, bone-cells, 

 bone-cells, and so on. 



These considerations on function all concern faculty or power; 

 but we have to notice now that the characteristic and funda- 

 mental form of power is to Mr Huxley contractility. He even 

 quotes Goethe in proof of contractility being the main power or 

 faculty of Man! Nevertheless it is to be said at once that, 

 while there are differences hi what protoplasm is contractile, all 

 protoplasm is not contractile, nor dependent on contractility for 

 its functions. In the former respect, for example, muscle, while 

 it is the contractile tissue special, is also to Mr Huxley proto- 

 plasm ; yet Strieker asserts the inner construction of the con- 

 tractile substance, of which muscle-fibre virtually consists, to be 

 essentially different from contractile protoplasm. Here, then, 

 we have the contractile substance proper " essentially different " 

 from the contractile source proper. In the latter respect, again, 

 we shall not call in the tmcontractile substances which Mr 

 Huxley himself denominates protoplasm bread, namely, roast 

 mutton, and boiled lobster ; but we may ask where even in 

 the case of a living body is the contractility of white of egg ? 

 In this reference, too, we may remark that Ktihne, who divides 

 the protoplasm of the epidermis into three classes, has been 

 unable to distinguish contractility in his own third class. Lastly, 

 where, in relation to the protoplasm of the nervous system, is 

 there evidence of its contractility ? Has any .one pretended 

 that thought is but the contraction of the brain ; or is it by con- 

 traction that the very nerves operate contraction the nerves 

 that supply muscles, namely ? Mr Huxley himself, in his Physi- 

 ology, describes nervous action very differently. There con- 

 duction is spoken of without a hint of contraction. Of the 

 higher faculties of man I have to speak again ; but let us just 

 ask where, in the case of any pure sensation smell, taste, touch, 

 sound, colour is there proof of any contraction? Are we 

 to suppose that between the physical cause of heat without 

 and the mental sensation of heat within, contraction is any- 

 where interpolated ? Generally, in conclusion here, while re- 

 minding of Virchow's testimony to the inherent inequalities of 

 cell-capacity, let us but, on the question of faculty, contrast 

 the kidney and the brain, even as these organs are viewed by 

 Mr Huxley. To him the one is but a sieve for the extrusion of 

 refuse : the other thinks Newton's ' Principia ' and Iliads of 

 Homer. 



Probably, then, in regard to any continuity in protoplasm of 

 power, of form, or of substance, we have seen lacunce enow. 

 Nay, Mr Huxley himself can be adduced in evidence on the 

 same side. Not rarely do we find in his essay admissions of 

 probability where it is certainty that is alone in place. He says. 



