Joseph Jackson Lister

“ The reticulum of channels of the plasmodium becomes meanwhile less and less marked. When the whole of the protoplasm is drawn in to the lobes, the circulation ceases. The lobes are the young sporangia. Meanwhile foreign bodies, taken in with the food, are ejected, and the protoplasm secretes on its outer surface a pellicle of mucoid, transparent substance which dries as the sporangia ripen. This invests the young sporangia, and as they rise above the substratum falls together at their bases forming the stalks ”

“ It has been stated (16) , but the observation requires confirmation, that a fusion of the nuclei in pairs occurs early in the development of the sporangium.
At a later stage, after the capillitium is formed, the nuclei undergo a mitotic division which affects all the nuclei of a sporangium simultaneously. This was first described by Strasburger (29) . While it is in progress the protoplasm of the sporangium divides, into successively smaller masses, until each daughter nucleus is the centre of a single mass of protoplasm. [7] These nucleated masses are the young spores. ”

“ A spore-wall is soon secreted and the sporangium has now resolved itself into a mass of spores, traversed by the strands of the capillitium and enclosed in a sporangium-wall, connected with the substratum by a stalk. As ripening proceeds, the wall becomes membranous and readily ruptures, and the dry spores may be carried abroad on the currents of air or washed out by rain. ”

“ It would appear therefore that the nutrition of plasmodia is effected in part by the ingestion of solid foodstuffs, and in part by the absorption of material in solution, and that there is great variety in the complexity of the substances which serve as their food. ”

“ They are found, stalked or sessile, in small clusters or distributed by the thousand over a wide area many feet in diameter, on the bark of decaying trees, on dead leaves or sticks, in woods and shrubberies, among the stems of plants on wet moors, and, generally, at the surface in localities where there is a substratum of decaying vegetable matter sufficiently moist to allow the plasmodium to live. ”

“ The plasmodia move slowly about over or in the substratum, concentrating in regions where food supply is abundant, and leaving those where it is exhausted.
On examining under the microscope a film which has spread over a cover-slip, the channels are seen to be streams of rapidly moving granular protoplasm. This movement is rhythmic in character, being directed alternately towards the margin of an advancing region of the plasmodium, and away from it. ”

“ The species of Mycetozoa are widely distributed over the world in temperate and tropical latitudes where there is sufficient moisture for them to grow, and they must be regarded as not inconsiderable agents in the disintegrating processes of nature, by which complex organic substances are decomposed into simpler and more stable chemical groups. ”