244 ZOOLOGICAL PHILOSOPHY 



universally injurious to animals living in the air, because it greatly 

 rarefies their essential fluids. It has thus been noted that in hot 

 countries, especially at the time of day when the sun is most powerful, 

 the animals appear to suffer, and hide themselves so as to avoid too 

 strong a glare. 



Aquatic animals, on the other hand, derive from heat, however 

 great it may be, results that are invariably favourable to their move- 

 ments and organic development. Among them, it is especially the 

 most imperfect such as the infusorians, polyps and radiarians that 

 benefit the most, since the condition is advantageous to their 

 multiplication and reproduction. 



Plants, which only possess a faint and imperfect orgasm, are in 

 absolutely the same condition as the aquatic animals of which I have 

 spoken : for, however great the heat may be, so long as these living 

 bodies have enough water at their disposal, they vegetate all the more 

 vigorously. 



We have now seen that heat is indispensable to the most simply 

 organised animals ; let us enquire if there are not grounds for the belief 

 that it may itself, with the co-operation of a favourable environment, 

 have fashioned the earliest rudiments of animal life. 



Nature, by means of heat, light, electricity and moisture, forms direct 

 or spontaneous generations at that extremity of each kingdom of living 

 bodies, where the simplest of these bodies are found. 



This proposition is so remote from the current notion on this matter, 

 that for a long time to come it is likely to be rejected as an error, and 

 even to be regarded as a product of imagination. 



But since men who are free even from the most ubiquitous pre- 

 judices, and who are observers of nature, will sooner or later perceive 

 the truth contained in this proposition, I wish to contribute towards 

 their perception of it. 



I beHeve I have shown by a collection of comparative facts, that 

 nature under certain circumstances imitates what occurs in sexual 

 fertilisation and herself endows with life isolated portions of matter 

 which are in a condition to receive it. 



Why indeed should not heat and electricity, which in certain countries 

 and seasons are so abundantly distributed throughout nature, especially 

 at the surface of the earth, not work the same result on certain sub- 

 stances of a suitable character and in favourable circumstances, that 

 the subtle vapour of the fertilising substances works on the embryos 

 of living bodies by fitting them for the reception of fife ? 



A famous savant (Lavoisier, Chimie, vol. i., p. 202) said with truth 

 that God, when he made hght, distributed over the earth the principle 

 of organisation, feeling and thought. 



