ABSTRACT
A study has been made of the drinking of soil moisture by two species of lycosid spider. Carborundum powders have been used to provide a ‘soil’ of uniform particle size.
The rate of drinking falls off with increase in the suction applied to the capillary water, finally becoming negligible, even though the soil remains saturated, at a suction which varies with the species of spider and possibly with the size of the individual.
This limiting suction is never reached if the capillaries empty at a lower suction.
The rate of drinking does not fall off with time, is similar for different individuals of the same species and size, and is not affected by soil particle size at a given suction, provided this is below the critical suction for the soil.
Throughout this paper the word ‘suction ‘is used when referring to the reduced pressure in the soil capillaries, and is measured in nun. Hg below atmospheric pressure. Also the word ‘soil’ is sometimes used to cover both natural soils and carborundum powders.
