PCT No. PCT/FR79/00128 Sec. 371 Date Oct. 6, 1980 Sec. 102(e) Date Oct. 6, 1980 PCT Filed Dec. 20, 1979 PCT Pub. No. WO80/01531 PCT Pub. Date Aug. 7, 1980.Device for trimming aristate seeds comprising a vertical spout wherein the seeds to be trimmed travel by gravity counter to a light air flow passing through one of the alveolate plates of a conveyer. In the flow-orientated position, the seeds are housed in one of the alveoli of the plate to be presented in this position to a trimming station comprised for example of a horizontal gas ramp positioned transversally to the direction in which the conveyer is translated.