XLIT.—ON BRANCHED HAIRS FROM THE STAMENS OF 
TRADESCANTIA VIRGINICA, sy Proressor M‘NAB, ».p., 
F.L8. Pate 20. 
[Read November 17th, 1879.] 
WHILE examining the hairs of Tradescantia in the Laboratory 
at Glasnevin, a flower-stalk was kept for sometime in water. 
The buds very slowly opened, and some of them remained per- 
sistently closed. On examining the hairs of one of the latter 
after the cut-stem had been in water for a fortnight, some of the 
hairs on the stamens were found to be abnormal. Four of these 
abnormal hairs were observed, three on one stamen, one on a 
second, and all in the same bud. 
Strasburger mentions :—“Zellbildung und Zelltheilung,” p. 
119, that the upper three cells of the filamentous hairs are capable 
of dividing, the round nucleus disappearing and two new ones 
forming. He does not mention having noticed branching hairs. 
As all the examples of branching differ one from the other, it is 
certain that under the abnormal condition in which the plant was 
placed, abnormal growth was the result. 
In No. 1 (Plate 20, Fig. 1) the second cell from the apex has 
pushed a new cell from the lower part. This has in turn divided, 
and a branch, having an entirely different axis of growth has 
been produced. From a careful examination of the specimen there 
can be little doubt that the side branch is the new axis, and not 
the main axis pushed aside. 
In No. 2 (Plate 20, Fig. 2) the third cell from the apex has 
produced a side cell, and thus assumed a somewhat triangular 
form. In No. 3 (Plate 20, Fig. 3) the sixth cell from the 
top pushes a new cell from the upper end; and in No. 4 
(Plate 20, Fig. 4) the second cell from the apex has formed a 
new side-cell at the upper part, pushing the true apical cell to 
one side. 
The moniliform hairs of Tradescantia are so very uniform in 
their mode of growth that these abnormal ones seem worth 
recording. 
ScriEN. Proc., R.D.S. Vou. 11, Pt. v. X 
