536 



THE BEGINNINGS OF LIFE. 



or ova throughout the atmosphere. 



valence of such forms of life is, however 



knowledge concerning the distribution of Jarge germs 



The great pre. 



easily 

 explicable in accordance with the possibility of their 



origin by more or less rapid series of ascending deve- 

 lopments^ or by processes of direct transformation of 

 vegetal vesicles. 



Thus it is^ as Pritchard says ^^ a well-known fact that 

 some Rotifers ^are common wherever water has re- 

 mained for a little time without disturbance —in 

 cisterns^ depressions in the gutters of houses^ saucers 

 of flower-potSj and similar situations.' And again^ in 

 a memoir published in 1 865 ^ On the Anatomy and 

 Physiology of Nematoids ^ I stated that ^ an examina- 

 tion of tufts of moss from the roofs of houses or from 

 old walls^ as well as of specimens of the yellow lichen 

 {Tarmelia parietlna) from the same situations^ has invari- 

 ably revealed to me three principal kinds of animal-occu- 

 pants — specimens of Rotifers^ of peculiarly slow-movin 



o 



arachnidal Tardigrada^ and two or three different kinds 

 of Anguillulid'X. Precisely the same varieties of animal 

 life are spoken of as existing in the tufts of moss 

 examined by Spallanzani^ and also in those which were 

 experimented upon by Andral and Gavarret. More- 

 over, I have found specimens of lichen brought from 

 Sweden tenanted by just the same types.' Now those 

 who believe that such forms of life are produced only 

 from pre-existing eggs of similar forms, must find it 



1 ' 



Infusoria/ p. 653. 



2 ( 



Philos. Trans.' 1866, p. 617 



(rthat 



ations or d 



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e9 



e '"^-D 



rep 



roduc( 



II 



m) 



ei similar 



that to whi 

 DEctioa with the 

 Jluslircom in sui 

 k of the f J ngi 

 tagh this becor 

 10 do with the lai 



toids'. No 



'Seep.iVv It is 

 »b be oUained at \\ 



'PWS5 which seem; 

 * is of ordinarj- s 

 *»f tie writings 

 ** J form of free Xe 



;*«rwards, ^ 

 '*'"'^« - having 

 ^' '* contained ■ 



Jltll 



'%ed 



found 

 ^ttite dip, 



reveal 





be. 



it, ,„ ^^ ^ liad 



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feci 



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