266 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



ranged. In Aneura [Riccardia] (17), Farmer and Moore describe 

 a transformation of the mother wall into a quadrilobed structure 

 during reduction. After the heterotypic karyokinesis a wall is 

 formed across the interzonal fibers; after the homoeotypic division 

 the respective lobes are delimited from each other at the center 

 of the original cell, by walls which take up the same position as 

 do soap bubble films when placed in boxes of corresponding form. 

 Ultimately fresh walls are formed around the content of each cell, 

 and the spores separate by the solution of the original walls. 

 Earlier (16a) Farmer had described quadripartition into four 

 tetrahedrally arranged spores in Pallavicinia and Aneura as 

 taking place only partially by cell-plates, "the cell- walls at their 

 inner angles grow into the cell-cavity," and the spores finally 

 become separated by the appearance of membranes. In Fossom- 

 hronia and Plagiochasma, he is uncertain as to the relation of cell- 

 plates to cell-division. He has also reported {I6d) quadripartition 

 by cell-plates in Fegatella [Conocephalum], in which they are in the 

 form of a rhomb, with five connecting spindles instead of six. In 

 all his work Farmer has omitted reference to the mother-cell-wall 

 and fails to show it in most of his drawings. 



The conditions which obtain in Anthoceros have been more 

 extensively studied and by more investigators. Von Mohl (43Z)) 

 first described the division by "auf der inncrn Seite der Zell- 

 wandung hervorsprossende Leisten . . . spater gegen die Mitte der 

 . Zelle zusammenwachsen und sich daselbst vereinigen" (pp. 282, 

 283). Schlacht (62) later (fig. 46) indicated centripetal develop- 

 ment of a cell-wall after the cleavage of the content (fig. 41). 

 Hofmeister (326) found the same procedure and studied it by 

 plasmolyzing the cell-content and observing the projection of 

 the new walls centripetally. He adds the interesting observation 

 that the mother-wall swells during the process of division. 

 Strasburger (67a) in the publication in which he established 

 the predominance of cell-plates in the cell-division of higher 

 plants by multiplying the cases of its occurrence, reports that 

 Anthoceros has in its spore formation a tetrahedral quadriparti- 

 tion by cell-plates, followed by a rounding up process. The 

 most recent work upon this genus is that of Davis (11). He 

 agrees that the quadripartition is tetrahedral, but notes that the 

 fibers crossing the division-planes are not parallel, but assume 



