154 Miscellaneous. 



are described the following new species of East Indian Sargassa, 

 Sargassum obovatum, S. Wightii and S. cervicorne. Drawings and 

 dissections were exhibited. The paper will appear in the ' Annals of 

 Natural History ' and in the Society's Transactions. 



5. "An Account of the Mosses and Hepaticae growing on the 

 Pyrenees," by Richard Spruce, Esq. (See p. 81 of the present 

 Number.) 



MISCELLANEOUS. 



On the Existence of an Ovum or Ovule as well in the Male as in the 

 Female of Plants and Aniinals ; producing in the one case Sperma- 

 tozoa or Pollen-grains, in the other the primitive Cells of the Embryo. 

 By Ch. Robin, M.D.* 

 The above-named memoir was submitted to a commission, consist- 

 ing of MM. Serres, Dumas, and Milne-Edwards, and the following 

 report has been drawn up and printed in the ' Comptes Rendus ' : 



" The facts contained in this memoir prove that, in the male or- 

 gans of plants and of animals, an ovule is formed, analogous to that 

 of the female, and constituted in a like manner ; that the vitellus of 

 this ovule divides as does that of the female, and by the same me- 

 chanism, giving rise to the development of the embryonary cells, which 

 after being modified by a special evolution constitute pollen-grains or 

 spermatozoa- Thus there is an analogy, and often an identity, be- 

 tween the product of the male generative organs and that of the 

 female. On the other hand, there is an identity in the mode of for- 

 mation of the embryonary cells in the ovum of vegetables and of ani- 

 mals ; and lastly, the mechanism by which the embryonary cells of 

 the male ovule (which are modified to constitute pollen-grains or 

 spermatozoa) are formed, is the same as that which gives birth to the 

 primary cells of the female ovum, the collection of which forms the 

 embryo. Thus the phfenomen m of the division of the vitellus, 

 figured and described for the first time among the Vertebrata by Pre- 

 vost and Dumas, may be extended to vegetables in an equal degree, 

 and it is the expression of a general and unique mechanism, according 

 to which the embryonary cells and zoosperms of all beings are formed. 



*' A. Analogy in the mode of formation of the embryonary cells in the 



ovules of animals and of vegetables. 



"1. It has been for along time admitted that the ovum of animals 

 appears among the cells of the Graafian vesicles, or the bottom of the 

 ovigerous tubes of the ovary, in the form of a small translucent cell, 

 the nucleus of which is represented by the germinal vesicle. By 

 degrees the transparent contents of the cell become granular and 

 opake, and constitute the vitellus. At this moment the ovum is 

 fitted for fecundation : it is still but a cell in a morphological point 

 of view ; physiologically speaking, however, it has a special nature, — 

 it is a product without an analogue in the body, and set apart for a spe- 

 cial function. On the occurrence of fecundation it becomes subject 

 to division, leading to the formation of embryonary cells at the ex- 



* The editors are indebted for this communication to J. T. Arlidge, 

 F.U.C.S.L. 



