抄録
As the technic for testing the susceptibility of Oncomelania snails to molluscicides two different methods are available; one is the plate method devised by McMullen (1949) and the other routine immersion one. The former was particulary devised for the screening purpose of molluscicides but is now utilized for the quantitative test of the susceptibility of snails. Considering theoretically, however, the latter would be better for the purpose, because the former, though simple in the procedure, implicates some shortness, which lies in the fact that here the snails get contact with chemicals only with a part of her body, that some snails move off the moist filter paper and that at times some of them ingest a considerable amount of filter paper. All such appear to interfere with the reproducibility of the effects. From such a viewpoint as mentioned above, a comparative examination on both methods was carried out.
For the establishment of the standardized technic, moreover, experimental study should be conducted to standardize the following subjects: a) the suitable length of time during which snails are in contact with chemicals, b) the suitable temperature at which snails are in the solution, c) the amount of the solution per snail during the test, d) the time of examining snails for their death. And finally the reproducibility of the standardized technic should be examined.
