V. Contributions to the study of the bionomics and reproductive processes of the foraminifera. 1

Abstract

The protozoologist who devotes himself to the study of the Testaceous Sarcodina 1 enters upon a task which is beset with difficulties which are, to a significant degree, insuperable. It is not so much the minuteness of the objects under consideration which is responsible for these difficulties, for, in the present and ever-advancing state of perfection of microscopical apparatus for the facilitation of technique, this is a difficulty which is more or less easily overcome. The mechanical difficulties are presented by the shell, which distinguishes the Foraminifera proper, the external skeleton of the organisms, which, whether they are calcareous, or whether they are arenaceous, that is to say, whether their shells consist of carbonate of lime separated from the surrounding media by some mysterious function of the protoplasm, or whether they are built together of fortuitous or selected materials, cemented together by a substance secreted by the organism, renders the examination of the living animal and the study of its life-history a task to which very definite limits are set. An examination, in the vast majority of species, of the nuclear conditions and changes can only be carried out upon individuals which are dead, and, at best, have been preserved in some recognised fluid (such as Schaudinn’s), the precise nature of the effect of which upon the dead protoplasmic body it is impossible accurately to calculate. The geographical difficulty is almost equally great, for many of the largest, and many, if we may use the word, of the “idiosyncratic” forms, are tropical species, having intimate relationships with species inhabiting temperate or even Arctic zones, and it becomes a physical impossibility to examine and compare these organisms alive, regard being had to the fact that to arrive at any satisfactory conclusions the observer must be on the spot to examine the animal when freshly gathered from the littoral zones, or dredged from considerable depths. In the latter case, it is unnecessary to advert to the difficulties inseparable from the work when carried out during the cruise of a surveying ship, however perfectly its laboratories may be equipped, and the best results that the biologist can attain are therefore to be derived from material preserved fresh upon such cruises, or from slides mounted with the haste inseparable from such work when carried out under such conditions.