334 Dr Eschricht's Ltg nines concerning 



reply, " This is altogether nonsense, the whole difference is 

 easily accounted for ; the sail and the bark turned round, and 

 caught the wind and current in a different direction.'' Were 

 mathematicians on the island, they might possibly find out 

 mathematical proofs that all was a simple consequence of gen- 

 erally prevailing laws. Limited, nevertheless, would be their 

 views, so long as they overlooked the harmony of the motions 

 resulting from the pilot's skill ; and not less limited is that ex- 

 plication of the phenomena of the living frame which refers 

 them all to the principles of mechanics, chemistry, and electro- 

 galvanism, independent of the presence of a vital power. 



I repeat, then, that the difficulty in tracing analogies between 

 the phenomena in the supposed spontaneous' generation and 

 the process of generation, lies not in the complication of the 

 processes, but in the harmony of the structure ; which may 

 be quite as perfect in organisms of the simplest structure as 

 in the others, and so sufficiently attest the presence of a 

 ruling principle. T/ie great difficulty^ upon the supposition of 

 equivocal generation^ lies in the origin of this principle. This 

 principle being present in the process of generation, and in 

 the formation of eggs, and wanting in a mixture of water, 

 earth, air, and caloric, that very point is wanting upon which 

 any analogy between such a spontaneous generation and com- 

 mon generation rests. 



Sect. 5. The Explanation of Equivocal Generation as p)roduced 

 hy a Latent Life refuted. — ^" But organic matter, it may be con- 

 tended, may at least retain somewhat of the vital power of the 

 living body from which it sprang, as is seen not only in eggs but 

 still more in the twigs of plants." True ; but as a hen*s 0:%^ 

 never produces any other animal than a chicken, and as a twig 

 of willow never becomes any other sort of tree, so a piece of 

 organic substance, if it retain somewhat of the vital power of 

 the organism whence it was taken, cannot become any other 

 sort of organism than that of the same species. It would be 

 ridiculous to suppose a serpent hatched from the Qgg of a hen , 

 or an oak springing from the twig of a willow, why then should 

 it not be as marvellous for a Vol vox globator, to arise from a 

 piece of beef \ In what respect is such a belief more probable, 

 more indicative of greater perfection of natm'al science in our 

 davs, than the belief of Aristotle that eels originated from 



