100 EXTRACTS FROM FOREIGN PERIODICALS. 



I; The development of the reproductive organs of Ceramium takes place 

 without any rupture of the envelop, but by extension of the tissue. The in- 

 ferior system, commencing from the root, is first developed. 



2. Whatever be the mode of fructification, and notwithstanding some appar- 

 ent or actual differences presented by the reproductive organs, the results are 

 precisely the same, that is, the reproductive organs formed by those of fructi- 

 fication, even though the latter differ greatly, produce equally the parent plant, 

 and in the same manner. 



3. Wherever there is agglomeration and condensation of colored matter, 

 there is formed a germ which reproduces the parent plant, sometimes even 

 before it is detached. 



4. Lastly, under certain circumstances, it is not even necessary that there 

 be agglomeration of coloring matter, the head being able, by its separation 

 from the parent stock, by a slip, to act as a conceptacle or organ destined to 

 prepare the reproductive parts, put forth radicles, and renew the species. 



This paper, of which we have given a brief summary, is accompanied by two 

 plates, illustrating the developments of the reproductive apparatus of several 

 species of Ceramium, and fully justifying the views of the author. — Biblio- 

 theque Univtrselle de Geneve* 



GEOLOGY. 



8. On some Interesting Phenomena relative to Ananchites and Spa- 

 tangus. — The royal mineralogical museum of Berlin contains two fossil spe- 

 cimens of Ananchites sulcatus, Goldf., similar to that described and represented 

 by Walch in Knorr's work on petrifications. The quartzose, cellular, and 

 remarkably regular structure of the interior of this fossil — whence it was 

 named, by old authors, after the cells of the Honey Bee— is explained by 

 another series of petrified echinites in the same collection. The surprising 

 regularity of these latter, precisely the same in a number of specimens, clearly 

 points out, that on each blade of the shell of the echinites is a crystal of cal- 

 careous spar, of which the axis is perpendicular to the blade, and the base 

 occupies its whole surface ; all the crystals seem ranged in a straight line with 

 the greatest regularity, diminishing in size towards the top of the echinite, and 

 increasing at top, all their axes converging to the interior of the shell. This 

 influence of the echinites upon the calcareous spar which crystallizes in their 

 interior, excites just surprise by its regularity. The form of the crystals is 

 rhomboidal. 



An echinite analogous to these is the Spatangus coranguinum, in which, on 

 the contrary, it is on the exterior surface of the shell that each blade has been 



