TULLEGREN FUNNEL

A dual-function unit for wet or dry extractions of arthropods, nematodes and similar motile organisms from soil in population studies.
Consists a plastic funnel, 200 x 140 mm, length x diameter, with an internal flange to support a plane wire gauze and a plastics soil-retaining cylinder, with open ends, for dry extraction or a dished wire gauze for wet extraction. A funnel support ring has an integral boss with clamping screw for mounting on a vertical support rod of up to 13 mm diameter. The funnel tappers to a 15 mm o.d. Tube at base and a length of rubber tubing with an adjustable screw clip is provided for attach-ment to tube for wet extraction. Also comprises a cylinderical lamp house, 300×110 mm, length x diameter, with an adjustable sliding b.c. Lampholder which accepts a lamp of up to 60 w and integral bosses, one with clamping screw, to enable attachment to a vertical support rod of up to 13 mm diameter.
As specified with funnel and lamphouse units, plane and dished wire gauzes, soil-retaining cylinder, length of rubber tubing with screw clip and instructions for use No. I.S. 1585. Without lamp and stand.
ACCESSORIES
Retort stand base, ‘A’ Shape, length of limb 210 mm.
Support rod, aluminium, 600 mm long.
EXPERIMENTAL NOTES
For dry extraction, a sample of soil is placed in the retaining cylinder on a gauze in the funnel. Heat and light from the lamp mounted above the funnel drive arthropods and similar organisms down through the gauze to a receiver placed below the funnel. The position of the lamp is adjustable to enable the temperature of the soil to be raised gradually thus preventing slower moving species from becoming trapped in hard, dry cakes of soil.
For wet extraction, the funnel is filled with water and the dished gauze containing the soil sample is placed in position. Nematodes and other swimming forms collect in the base of the funnel and can be drawn off at intervals by opening the screw clip. This method can also be used for extracting nematodes from plant tissue such as patato affected by eel-worm.