4 EXPERIMENT STATION RECORD. 



invariable transmission of ancestral characteristics. He thinks that 

 the cutting- will produce an individual subject to variation to just the 

 extent that the new conditions of life prove more advantageous than 

 the old. This applies equally to reproduction by grafts or from cuttings. 



A difficulty in physiological experimentation has recently been i^ointed 

 out by Prof. Eaulin,' of the University of Lyons. He has demonstrated 

 that the chemical nature of the soil influences the seed of plants grown 

 upon it, and this influence may be felt for many generations. In this 

 way some of the widely divergent results of experiments may be 

 explained. 



Due weight must be given to such preliminary considerations, since 

 we can not be too carefwl in determining all the conditions likely to 

 alfect the results of agricultural experiments. If we wish to give true 

 scientific exactness to tho results, it is necessary to avoid the sources 

 of error of every sort whieh are so numerous in biological researches. 



Liebig was the first to formulate clearly the role of water. He stated 

 the function to be twofold. It is a food material and also an assistant 

 to the growth of plants.^ The protoplasm of the cell, as well as the 

 cell walls, contains a certain amount of water. In other words, water 

 is an integral part of the cell in certain definite pro^iortiojis. These 

 proportions must be maintained or the plant suffers. 



As water is furnished tbe plant by the soil, we shall discuss consecu- 

 tively the two following jioints: Water of the soil and water of the 

 plant, adding finally some suggestions relative to irrigation. 



WATER IN THE SOIL. 



Water acts in 3 different ways. It exercises a physical action and 

 is at the same time a chemical and a biological agent, the nature of its 

 action varying with the quantity present. 



The soil receives water by precipitation and by absorption. It loses 

 it by evaporation and drainage. The difference between the loss and 

 gain constitutes the reserve for the use of plants. Many methods have 

 been proposed for the estimation of the extent of this reserve, among 

 others by Maurice de Geneve (1797), Gasparin (1822),-^ and Pagnoul 

 (1880).'' The method of the latter consists of direct weighing or measur- 

 ing in the case of small plants. A method proposed by Director Kisler,^ 

 of the Agronomic Institute of Paris, consists of measuring the flow from 



'Ann. Sci. Agron., ser. 2, 1 (1896), p. 410; Jonr. Agr. Prat., 60 (1896), Nos. 30, p. 113; 

 31, p. 151. 



-See also Recherclies snr le role physiologi(]ue de I'eau dans la veg<^tation, Ann. 

 sci. uat. Bot., 1895; Modes d'action de Teau du sol sur la vegetation. Rev. gen. Bot., 

 7(1895), pp. 71-138. 



^Gasparin, Cours d'Agriculture, vol. 1. 



■• Pagnoul, Ann. Agron., vol. 7 (1881), p. 20; Bui. Meteorologique du Pas de Calais, 

 1880. 



'^Risler, Evaporation du sol et les i)lante8; Archiv. sci. Bibliotheque universelle, 

 1879. 



