A Second Contribution to our Knowledge of the Anatomy 
of the Cone and Fertile Stem of Equisetum. 
BY 
ISABEL M. P. BROWNE. 
With Plates XII-XIV and five Figures in the Text. 
I should like to prefix to this Second Contribution an expression of 
regret that, owing to a printer’s error, Text-fig. 2 of my earlier paper on 
Equisetum was printed upside down (Browne, p. 669). 
Material. 
HE present investigations were confined to Equisetum maximum , Lam. 
JL (E. Telmateia , Ehr.). Two complete cones were cut serially into 
transverse sections; these I shall henceforward term Cones A and B. 
Cone A was young; about one-half of it was covered by the uppermost 
whorl of leaves of the fertile stem. Including the terminal group of un¬ 
differentiated or congenitally concrescent sporangiophores, the length of 
the cone was about 1*5 inches ; the actual height of the axial stele, a longi¬ 
tudinal reconstruction of the xylem of which was made, was 1-15 inches. 
At its widest the stele of the axis of this cone had a diameter of about 
4*75 mm. At the lower end the destruction of the pith—owing to the 
growth in diameter of the stem—had only just been initiated. The degree 
of disturbance of the central cells of the pith varied a little locally, but 
relatively few cells were involved, and at this early stage the pith cannot be 
said to be definitely fistular in any part of the cone. As we pass upwards 
the cells of the pith gradually cease to be destroyed or to suffer distortion. 
Cone B was a very large one and fully mature, though the apical { drip- 
point ’ remained, as it seems always to remain, externally undifferentiated 
into distinct sporangiophores. The longitudinal reconstruction of the xylem 
extended from the supra-annular fusions (Browne, p. 690-4) to the point 
at which a single, large, terminal strand enters the terminal ‘ drip-point ’, 
a height of just under three inches ; including the latter, the height of the 
cone was over three inches. Though this cone was large, it was by no means 
exceptional in respect of its size. Of a branching cone, C, the upper 
part, which included the region of branching, was cut serially. The region 
[Annals of Botany, Vol. XXIX. No. CXIV. April, 1915.] 
