| 摘要 |
<p>This apparatus has a sieve (4) with a wall (22) perforated with a multitude of holes, means (4, 5) for holding a removable receptacle (20) containing a layer of gel growth medium (21) and means (7, 8) for sucking in air at the periphery of the receptacle (20) in order to cause to enter the apparatus (1), through holes in the wall (22), air which strikes the layer of gel growth medium (21), the latter and the wall (22) being shaped so that their separation increases from their periphery towards their centre. <IMAGE></p> |
