The Apical Cell of Fucus 1 . 
BY 
W. M c MICHAEL WOODWORTH. 
With Plate X. 
I WAS induced to undertake the work, the results of which 
are embodied in this paper, by the state of confusion 
that exists in our present knowledge of the apical growth of 
the Fucaceae. My work was more especially stimulated by 
the disparity between the results ( arrived at by Reinke and by 
Rostafinski, two investigators to whom is due much of the 
information that we have upon the so-called apical cells of 
Fucus. 
Reinke 2 , whose results are based upon the study of Fucus 
vesiculosus , holds that the growing-point of Fucus vesiculosus 
consists of a group of cells uniform in structure, but that one 
of them is characterized by being larger than the others of the 
group. The protoplasm of the whole group of cells is denser 
than that of the other cells, and their walls are thinner. 
Dichotomy, or branching of the stem, according to Reinke, 
results from a more active growth at the edge of the growing 
cells; that is, cell-proliferation is more energetic at two points 
on the edge of the group, the points being opposite to each 
other in the direction of the elongated depression at the tip. 
1 The investigations of which the following pages are a record were carried 
on under the direction of Dr. W. G. Farlow, at the Cryptogamic Laboratory 
of the Museum of Harvard University, Cambridge, Massachusetts, U.S. A. 
2 J. Reinke, Beitrage zur Kenntniss der Tange, in Pringsheim’s Jahrb. fiir Wiss. 
Botanik, x. (1876), p. 341. In the notes to this paper a bibliography of the older 
works on the subject under consideration is given. 
[ Annals of Botany, Vol. I. Nos. Ill and IV. February 1888.] 
Q 
