SPONTANEOUS GENERATION 237 



the maintenance of life, but that it could even create both life and 

 organisation. 



They recognised then that direct generations do occur, that is 

 to say, generations wrought directly by nature and not through the 

 intermediary of individuals of a similar kind : they called them 

 somewhat inappropriately spontaneous generations ; and perceiving 

 as they did that the decomposition of animal or vegetable substances 

 provided nature with conditions favourable to the direct creation of 

 new organisms, they wrongly imagined that such organisms were the 

 produce of fermentation. 



I am in a position to show that the ancients were not mistaken when 

 they attributed to nature the faculty for direct generation ; but that 

 they were very much mistaken in applying this moral truth to a number 

 of living bodies, which neither are nor can be produced by this sort 

 of generation. 



As a matter of fact, sufficient observations had not then been collected 

 on this subject ; and it was not known that nature, by means of heat 

 and moisture, directly creates only the rudiments of organisation. 

 This direct creation is confined to those living bodies which are at the 

 beginning of the animal and vegetable scales, and perhaps of some of 

 their branches. Thus the ancients, of whom I speak, thought that all 

 the animals with low organisations — which they called for this reason 

 imperfect animals — were the result of these spontaneous generations. 



Lastly, since natural history in those tim.es had scarcely advanced 

 at all, and very few facts had been observed as to the productions of 

 nature, the insects and all the animals then designated as worms were 

 generally regarded as imperfect animals, which are born in favourable 

 times and places, as a result of the action of heat on various decaying 

 substances. 



It was then believed that putrid flesh directly engendered larvae, 

 which were subsequently metamorphosed into flies ; that the extra- 

 vasated juice of plants, which, as a result of pricks by insects, gives 

 rise to gall nuts, directly produced the larvae which are transformed 

 into Cinips, etc., etc. : all of which is without foundation. 



Thus the mistake of the ancients in assuming direct generations 

 in cases where they do not occur, was propagated and transmitted 

 from age to age ; it was bolstered up by the erroneous beliefs named 

 above, and became the cause of a new mistake for moderns after they 

 bad recognised the old one. 



When people perceived the necessity for collecting facts and making 

 precise observations as to what actually occurs, the mistake into which 

 the ancients fell was disclosed : men famous for their attainments 

 and powers of observation, such as Rhedi, Leuwenhoek, etc., proved 



