250 PROFESSOR OWEN ch. vm. 



end which the best anatomists and physiologists 

 have in view. 



4 I have cited experiments in my " Lectures 

 on the Invertebrata" published last year, in 

 which infusions of dead organic matter, light, 

 warmth, atmospheric air — in short, all the con- 

 ditions requisite for the supposed spontaneous 

 development of animalcules — were present, but 

 with an adequate contrivance against the possi- 

 bility of the presence of the ova of such, and no 

 development ensued. I have had personal experi- 

 ence — but the case would be too long for this 

 letter of acknowledgment — of the inadequacy of 

 the preventive means adopted by Mr. Crosse ; the 

 like inadequacy of Mr. Weeks's may be inferred 

 from his own description. I have sought in 

 every department of animated nature for un- 

 equivocal evidence of the earth and the waters 

 still exercising those delegated powers to which 

 the Mosaic record refers, that rich " bringing 

 forth of the moving creature that hath life" at 

 the earliest periods of the peopling of this planet, 

 but hitherto in vain. The gradation of organic 

 beings is for the most part so close and easy that 

 we cannot be surprised at the idea of progressive 

 transmutation of species having been a favourite 

 one with the philosophic mind in all ages. When, 

 however, you refer the highest species of the 

 Quadrumana to the Indian Archipelago, and con- 

 nect the fact with the origination of man (page 



