The nearest analogue to this remarkable partnership is to be found in the vegetable kingdom, where, as the researches of Schwendener, Bornet, and Stahl have shown, we have certain algæ and fungi associating themselves into the colonies we are accustomed to call lichens, so that we may not unfairly call our agricultural Radiolarians and anemones _animal lichens_. And if there be any parasitism in the matter, it is by no means of the alga upon the animal, but of the animal, like the fungus, upon the alga. Such an association is far more complex than that of the fungus and alga in the lichen, and indeed stands unique in physiology as the highest development, not of parasitism, but of the reciprocity between the animal and vegetable kingdoms. Thus, then, the list of supposed chlorophyl containing animals with which we started, breaks up into three categories; first those which do not contain chlorophyl at all, but green pigments of unknown function (_Bonelia<, Idotea_, etc.); secondly, those vegetating by their own intrinsic chlorophyl (_Convoluta_, _Hydra_, _Spongilia_); thirdly, those vegetating by proxy, if one may so speak, rearing copious algae in their own tissues, and profiting in every way by the vital activities of these. PATRICK GEDDES. * * * * * COMPRESSED OIL GAS FOR LIGHTING CARS, STEAMBOATS, AND BUOYS. We give in the accompanying figures the arrangement of the different apparatus necessary for the manufacture and compression of illuminating gas on the system of Mr. Pintsch, as well as the arrangements adopted by the inventor for the lighting of railway cars and buoys. This system has been adopted to some extent in both Germany and England, and is also being introduced into France. [Illustration: WORKS FOR THE MANUFACTURE OF OIL GAS.--ELEVATION AND PLAN.]