232 EAMBLES OF A NATURALIST. 



the same manner as Infusoria ; and finally we might 

 instance those spores of the freshwater Algae, true 

 vegetable larvae, which, before they become finally 

 fixed, move freely about in the glass in which we are 

 observing them ; thus appearing to realise the meta- 

 morphosis of an animal into a plant. We should 

 thus observe the gradual disappearance of all those 

 well-marked differential characters by which our 

 predecessors in their imperfect knowledge attempted 

 to fix the limits of the two kingdoms of nature, 

 and we should find that all such distinctions vanish, 

 not excepting even those derived from chemistry, as 

 has been proved by M. Payen's * curious analyses 

 of young tissue, and by the remarkable phenomena 

 which accompany the fecundation of the Arum, f 



* M. Payen, a member of the Institute and professor at the 

 Conservatoire des Arts et Metiers, is one of our most distinguished 

 chemists, whose name has become popular in consequence of the 

 practical utility of the greater number of his works. In the 

 memoir to which we have referred, M. Payen shows that at the 

 moment of their first appearance, the young vegetable tissues are 

 fully as nitrogenous as the animal tissues, and that it is only in grow- 

 ing older that they become overcharged, so to speak, with carbon. It 

 had hitherto been supposed that one of the essential differences 

 between the two kingdoms consisted in this that nitrogen pre- 

 dominated in the chemical composition of animals, as carbon does 

 in the chemical composition of vegetables ; it is obvious, however* 

 from M. Payen's researches, that this idea must now be abandoned. 



f Lamarck and Bory de Saint- Vincent were the first who drew 

 the attention of naturalists to the development of heat which 

 accompanies fecundation in several species of the family of the 

 Aroidese, and this phenomenon has been studied with much care 

 by several observers, and amongst others by Beck and Bergman. 

 These experimentalists have observed in certain cases that the 

 temperature of the Spadix rose to 109 4' Fahrenheit, whilst the 

 surrounding air stood at only 70. In the Arum cordifolium, the 



