12 EEYTHEA. 



which has long been keenly felt. Like the father of one of 

 the authors, 'I love to exalt plants' (i, 98). I have long 

 been satisfied that the facts of vegetable physiology are capa- 

 ble of being widely taught, and are not less significant and 

 infinitely more convenient than most of those which can be 

 easily demonstrated on the animal side. How little any 

 accurate knowledge of the subject has extended was con- 

 spicuously demonstrated in a recent discussion at the Eoyal 

 Society, when two of our foremost chemists roundly denied 

 the existence of a function of respiration in plants, because 

 it was unknown to Liebig ! 



Assimilation. 



The greatest and most fundamental problem of all is that 

 of assimilation. The very existence of life upon the earth 

 ultimately depends upon it. The veil is slowly, but I think 

 surely, being lifted from its secrets. We now know that 

 starch, if its first visible product, is not its first result. We 

 are pretty well agreed that this is what I have called a 'proto- 

 carbohydrate.' How is the synthesis of this effected? Mr. 

 Acton made some remarkable researches, which were com- 

 municated to the Royal Society in 1889, on the extent to 

 which plants could take advantage of organic compounds 

 made, so to speak, ready to their hand. Loew, in a remark- 

 able paper, which will perhaps attract less attention than it 

 deserves from being published in Japan,^^ has, from the 

 study of the nutrition of bacteria, arrived at some general 

 conclusions in the same direction. Bokorny appears 

 recently to have similarly experimented on algse. Neither 

 writer, however, seems to have been acquainted with Acton's 

 work. The general conclusion which I draw from Loew, is 

 to strengthen the belief that form-aldehyde is actually one of 

 the first steps of organic synthesis, as long ago suggested by 

 Adolph Baeyer. Plants, then, will avail themselves of 

 ready-made organic compounds which will yield them this 

 body. That a sugar can be constructed from it has long 



35J5mW. College of Agric Imp. Univ. Tokio, vol. ii. 



