The Branching and Branch Shedding of 
Bothrodendron. 
BY 
MARJORIE LINDSEY. 
With Plate XI and three Figures in the Text. 
Introduction. 
HE object of this paper is to bring forward some new evidence with 
A regard to the ulodendroid scars of Bothrodendron , and to discuss the 
ulodendroid condition both in this genus and in Lepidodendron. 
From very early in the history of Palaeobotany these two genera have 
been known to bear, in certain cases, two opposite rows of depressed circular 
scars on their main stems. 
Such stems were said to be in the ulodendroid condition, and practi¬ 
cally every possible type of appendicular organ has, at one time or another, 
been suggested as the cause of the scars. 
The various theories regarding the ulodendroid scars may therefore 
be grouped under five heads, representing the five possible types of appen¬ 
dicular organ. 
We have then :— 
1. The floral theory , put forward by Rhode, and agreed to by Allan (1), 
who compared the plant with a cactus. 
2. The root theory , first suggested by Brongniart and more fully discussed 
by Carruthers (3). This was refuted by Williamson (14) and 
Thompson (11). 
3 . The bulbil theory of Stur ( 10 ), which was in its turn refuted by 
Schimper ( 8 ). 
4 . The cone theory due in the first place to Lindley and Hutton (5), but 
confirmed by many others, notably Thompson (11). For long this 
was the accepted theory, but it has recently been shown to be impro¬ 
bable by Watson (12) and Renier (7), who prefer 
5 . The branch theory , originally due to Sternberg. 
[Annals of Botany, Vol. XXIX. No. CXIV. April, 1915.] 
