The Mollusc Fauna of Glasshouses in the Netherlands

Many publications seem to be written for no purpose at all, descending unexpectedly on a more or less surprised scientist who takes notice of the facts, wondering just what to do with his newly acquired knowledge. The origin of the researches laid down in this paper is easily retraceable to the inspiring publications of Baas Becking¹), who has pointed out the truth in the words of Beijerinck, that, if we limit our attention to the study of micro-organisms, „everything is everywhere”. The authors of this publication hold the firm belief that if we keep an eye on the perpetual though not always praiseworthy activities of mankind, micro-organisms as well as higher organised beings may arrive at some time or another at every possible place on earth by means of ships, caravans, motor cars, railway carriages, aircraft or any other form of traffic, if only given time. The establishment of a certain organism at the place of arrival furthermore only depends on the presence of a suitable milieu for the development and propagation of the given species in that particular place.