8. In connection with a determination of the germinating ability of sp in competition with normal pollen it was found that pollen could be germinated by placing it on sucrose-agar (10% sucrose and .7% agar from Andronescu, 1915) in depression slides. The method seemed to be applicable, however, only if the humidity is low, since trials in the early summer when the humidity was very high resulted in failure as the pollen grains would burst before germination started.

F. J. Clark