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150 NATURE AND AFFINITIES OF THE SPONGES.the several protests against the views submitted by Professor Haeckel,reference may be made to the communications contributed by the presentauthor to the 'Annals of Natural History' for March and August 1870.The subject on these occasions was approached more entirely fromthe Ccelenterate point of view, the writer being at that time officiallyoccupied in the study, identification, and arrangement of the series ofcorals, recent and fossil, contained in the Natural History Departmentof the British Museum. Arguing from such a standpoint, it was soughtto demonstrate that between the alimentary systems of the two groupsin question there was nothing whatever in common ;that the single,well-defined gastrovascular aperture in a coral, subservient both for theprocesses of ingestion and excretion, was in no ways comparable to themultifarious canal-system through which, upon every side of its periphery,the sponge-body received its nutriment, and that the assumption byProfessor Haeckel of a distinct ectoderm and endoderm in the structuralelements of a sponge was by no means clearly demonstrated. His claimof a distinct personality for each oscular area of a sponge-body waslikewise contested, and an adhesion given generally to that Protozoicinterpretation of the sponge question, then supported in the text-books ofHuxley, Carpenter, and other English authorities, and manifested by theinvestigations of Lieberkuhn, Bowerbank, and Carter, and especiallythrough the more recent investigations of Professor H. James-Clarkalready quoted. Evidence of a still more substantial nature, tending inthe same direction, and emanating from one of the earliest and firstauthorities in this country upon sponge organization,noticed.has next to beIn October 1871, Mr. H. J. Carter contributed to the 'Annals ofNatural History ' the announcement of his identification, in all of thenumerous marine siliceous and calcareous sponge types recently examinedby him, of a structure essentially corresponding with that which hepreviously described as obtaining in Spongilla, and generally indicatedtheir nonconformity with the Coelenterate plan of organization insisted onby Professor Haeckel. As interpreted by Mr. Carter, the " ampullaceoussacs," or other ciliated systems, represented the only essential portion ofthe sponge structure, the remaining elements compared with these beingentirely subsidiary. One especially weak point in Professor Haeckel'sargument was further pointed out in his remarks concerning the sexualityof the sponges. In none out of the hundreds of Calcispongiae examinedby him with the microscope, Haeckel says, could he detect a trace offecundatory male elements or zoospermia, and that therefore the bodiessubserving the purposes of reproduction constantly present cannot bedesignated true sexual eggs or ova, but asexual germ-cells or "spores."These spores, or so-called ova, in all the sponges he investigated, ProfessorHaeckel, moreover, declared to be perfectly naked and destitute of membrane,like the flagellate cells from which they proceed ; furthermore, he