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NOTICES OF BOOKS. 

 The Fertilization and Development of Floride^. 



The Botanische Zeitung, for August, 1898, contains the results 

 of an interesting investigation by Prof. Oltmanns, entitled " Zur 

 Entwickelungsgeschichte der Florideen, " with four plates. The 

 Schmitzian theory — we may even say assertion — of a second act 

 of fertilization in the development of the Floridean cystocarp has 

 never been accepted with the same faith as the other conclusions 

 of this lamented phycologist. This is only natural, since, as Prof. 

 Oltmanns says, " If a double fertilization took place, what would 

 become of all the theories of heredity &c. " ? These considerations 

 led Prof. Oltmanns to re-examine some of the alg^ described by 

 Prof. Schmitz, and his results show that in no case does any double 

 act of fertilization take place. The first alga described in this paper 

 is Dadresnaya purpurifera, as being a well-known example of those 

 algae which produce ooblastema-filaments ; and the development of 

 the fruit is followed from the earliest stages. This has of course 

 been described and figured by Messrs. Bornet and Thuret and others, 

 but till now the further conduct of the sporogenous nucleus has 

 never been accurately followed. By the term "sporogenous nucleus" 

 (sporogener Kern) Prof. Oltmanns designates the nucleus which is 

 the result of the fusion between the male nucleus of the spermatium 

 and the female nucleus of the carpogonium. On the behaviour of 

 this sporogenous nucleus hangs the decision whether or no a 

 secondary act of fertilization takes place— provided always, that 

 *' fertilization " is understood to involve a fusion of nuclei. 



The fertilized carpogonium of Dudresnaya purpurifera begins to 

 swell, and to produce certain outgrowths which are called by Prof. 

 Schmitz '' ooblastema-filaments." This term is discarded by Prof. 

 Oltmanns, as indicating the idea of fertilization, and his own new 

 term " sporogenous-filaments " is used instead. From the fertilized 

 carpogonium there grow out then 2-3 sporogenous-filaments, one 

 at each side and sometimes a third in the middle. These grow 

 downwards towards the terminal cells of the small Callithaimiion- 

 like_ branches, which have grown out from the axis of the carpo- 

 gonial branch. Fusion takes place between the sporogenous branch 

 and the terminal, as well as the subterminal, cells of these branches 

 — the auxiliary- cells. As is shown by the figures, that portion of 

 the sporogenous-filament which fuses with the auxiliary-cell is cut 

 off by a cell wall. The protoplasm of the sporogenous cell fuses 

 with that of the auxiliary-cell, but so far from there being any fusion 

 of the two nuclei, there appears to be a desire on the part of the 

 auxiUary-cell nucleus to shrink away as far as possible from the 

 sporogenous nucleus. Before the cell fusion takes place, the nuclei 

 of the auxiliary-cells are in the middle of their respective cells ; but 

 so soon as the dividing walls are broken down, the auxiliary nucleus 

 (if one may use the term) flees before the sporogenous nucleus to 

 the most distant corner of its cell. This was found to occur in 

 every specimen examined by Prof. Oltmanns, 



