The process of fertilization in Aspidium and Adiantum

Abstract

The investigations of Ikeno, Hirase, Webber, and Shaw have given increased interest and importance to all facts bearing on the process of fertilization in plants. This interest centers on those groups which mark the boundary line between the lower and the higher forms. The correspondence between the results of Ikeno's work on Cycas revoluta and those of Shaw on Onoclea makes necessary a close study of the details of the fusion of the egg and spermatozoid for related forms. Previous investigations in both animals and plants have shown the spermatozoid as losing its distinct character and assuming the form and appearance of a resting nucleus of equal or nearly equal size with the nucleus of the egg before their final fusion. Ikeno and Shaw, on the contrary, have described the actual entrance of an unchanged spermatozoid nucleus into the nucleus of the egg which is found in the usual resting stage.