126 ON EQUIVOCAL GENERATION. 



Microscopic vegetables and animals remaining without any 

 visible sign of lite months and years is no proof that they were 

 capable of deriving their origin from dead unorganized matter. 

 While their organization is not destroyed, the motions which 

 indicate life may be restored by proper degrees of heat and 

 moisture ; but this is not materially different from the case of 

 frogs and other animals, which discover no sign of life, a 

 great part of the winter, and revive with the warmth of 

 spring. 



That any thing composing an animal or vegetable should, 

 after affording nutriment to other animals, attain some kind of 

 organization, or even vitality, may be admitted; because the 

 digestive powers of animals may not be able to destroy their 

 organization, or vitality. But if it remain uninjured, and be 

 afterwards revived, it cannot be any thing besides the very 

 same organization that it had before. So birds feed upon seeds, 

 which yet retain so much of their organization", and life, as 

 to be able to produce the plants from which they came, but 

 never any of a different kind. Beyond this no analogy in 

 nature can carry us. 



'* These microscopic organic bodies," he says, p. 8. " are 

 " multiplied and enlarged by solitary re-production, without 

 " sexual intercourse, till they acquire greater perfection, or 

 " new properties. Liewenhook observed in rain-water which 

 " had stood a few days, the smallest scarcely visible animal- 

 " cules and in a few days more he observed others eight 

 M times as large." But this proves nothing more than an in- 

 crease in bulk, and no change of a small animal into a larger 

 of a different kind, which the argument requires. If it was 

 the same animal that assumed a new form, in a more advanced 

 state, it is no more than the case of a tadpole and a frog, or a 

 caterpillar and butterfly. That several insects are multiplied 

 without sexual intercourse is no proof of spontaneous generation. 

 Plants are several ways produced without seeds; and according 

 to Dr. Darwin's observations, this mode of animal re-production 

 has its limits. For that after a certain number of such gene- 

 rations the last discover the properties of se.v, and then produce 

 others by sexual intercourse, so that it is probable, that if at 



