ZOOLOGY AND BOTANY, MIOEOSCOPY, ETC. 693 



as also in the further development of the fertile cell. In some cases 

 the protoplasmic contents of the two cells (fertile cell and auxiliary 

 cell) coalesce, the nuclei remaining distinct ; in others the union is 

 complete. The cell resulting from this conjugation then displays 

 rapid growth, and marginal cells divide off from it, leaving a large 

 central cell ; this central cell alone remains sterile ; all the rest, 

 which form a dense envelope around it, j)roducing carpospores, the 

 whole structure constituting a complicated cystocarp. In the Coral- 

 linacese the process is similar, but somewhat more complicated, the 

 ooblastema-filament of the oospore entering into successive conjuga- 

 tion with several neighbouring auxiliary cells. In a very large 

 number, perhaps a majority, of the Floridefe, including the CeramiaceEe, 

 Wrangelie83, Ehodomelefe, Chylocladiefe, Ehodomenieaa, Sphferococcae, 

 and Gigartinea3, the mode of formation of the cystocarp is, with 

 modifications in the different groups, as follows : —A short branch of 

 the carpogonium, usually consisting of three or four cells, becomes 

 attached laterally to a branch of the thallus, and becomes curved in 

 such a way that the carpogonium-cell is closelyapplied to the nearest 

 auxiliary cell, or reaches it by means of a short protuberance from 

 one or both of the conjugating cells. The entire protoplasm, or at 

 all events the nucleus, of the oospore, then passes over into the 

 auxiliary cell, which then developes into the cystocarp in different 

 ways in the different groups. In the Gigartine^, the auxiliary cell 

 itself becomes the central cell of the cystocarp. 



As a general result of these observations, Schmitz asserts that in 

 the Floride^ there is invariably a material conjugation between the 

 male cell or spermatium and that cell which developes into the 

 sporiferous tissue of the cystocarp (the " nucleus " of systematists). 

 Nowhere has he ob.^erved any indirect fertilizing action of the 

 conjugation of spermatium and carpogonium on a third distant cell. 



The remarkable phenomena here described appear to point to a 

 double process of impregnation in the same individual occurring in 

 many Floridese ; first of the male spermatium with the female carpo- 

 gonium cell, secondly of the oospore or fertilized contents of the 

 carpogonium with one or more auxiliary cells ; and the author 

 discusses this hypothesis at length. He points out that in the 

 simplest case the contents of the oospore pass, without any inter- 

 mediate formation of ooblastema-filaments, into the auxiliary cell; 

 and this process appears to form a connecting link between an ordi- 

 nary process of absorption of nutriment and an act of sexual union. 

 If an act of sexual conjugation is regarded simply as a strongly 

 specialized instance of absorption of nutriment, then the repetition 

 of this process in a single individual ceases to have the exceptional 

 character which would otherwise belong to it. In the simplest forms 

 as Nemaleon, the second process is altogether wanting, and the de- 

 velopment of the cystocarp corresponds closely to that of the sporo- 

 gonium in Muscineje, and might even be regarded as displaying a 

 kind of alternation of generations. In some groups of Floride^ this 

 alternation of generations is further complicated by the production 

 of non-sexual individuals, or those that bear tetraspores, these not, 



