CONTINUITY. 2ii 



with larger organic beings. The controversy between M. Pas- 

 teur and M. Pouchet has led to a very close investigation of 

 this subject, and the general opinion is, that when such; pre- 

 cautions are taken as exclude from the substance submitted to 

 experiment all possibility of germs from the atmosphere being 

 introduced, as by passing the air which is to support the life 

 of the animalculse through tubes heated to redness and other 

 precautions, no formation of organisms takes place. Some 

 experiments of Mr. Child's, communicated to the Royal 

 Society, again throw doubt on the negative results obtained 

 by M. Pasteur ; so that the question may be not finally de- 

 termined, but the balance of experiment and opinion is 

 against spontaneous generation. 



One argument presented by M. Pasteur is well worthy of 

 remark, viz. that in proportion as our means of scrutiny 

 become more searching, heterogeny, or the development 

 of organisms without generation from parents of similar 

 organism, has been gradually driven from higher to lower 

 forms of life, so that if some apparent exceptions still exist 

 they are of the lowest and simplest forms, and these ex- 

 ceptions may probably be removed, as M. Pasteur considers 

 he has removed them, by a more searching investigation. 



If it be otherwise, if heterogeny obtains at all, few will 

 not now admit that at present the result of the most careful 

 experiments shows it to be confined to the more simple 

 organic structures, and that all the progressive and more 

 highly developed forms are, as far as the most enlarged 

 experience shows, generated by reproduction. 



[It has seemed to some an inconsistency that an advocate 

 of continuity or gradual hereditary change in organisms 

 should not be in favour of heterogeny, since, if highly com- 

 plex organisms be formed by gradual evolution from more 

 simple structures, we should ultimately reach a point at which 

 organised forms should be developed from inorganic matter. 



This may be so, could we go far enough back in the his- 

 tory of genesis ; but what I look on with some degree of scep- 

 ticism is the development of complex though minute organ- 

 isms which appear, so to speak, full-blown at their inception, 

 and perfectly capable of reproduction, though not themselves 



p 2 



