43 
The So-called Phloem of Lepidodendron. 
degeneration or other changes, which would tend to obliterate the 
original structure before petrifaction took place. The tissue in 
question may or may not have had a secretory function, but such 
anatomical evidence as we have before us does not appear to me to 
support the view that Lepidodendron possessed a phloem-tissue 
essentially similar to that of its recent allies. I entirely agree 
with the opinion that this band of tissue external to the cambium 
may have acted as phloem, but we require additional data before we 
can assert that it carried out its share of the plant’s requirements 
Figure 1. Lepidodendron Wunschianum. 
Transverse vSection. T , small tracheal and partially developed xylem 
elements; C, Meristematic Zone ; S, Secretory Zone. 
by means of tissue-elements like those in the phloem of recent 
plants. 
I will now pass on to the extra-cambial region in the stele of 
the Lepidodendron from Dalmeny. This stem is referred to in 
Professor Weiss’ paper, but it is dealt with rather more fully by 
Dr. Scott, who has published a figure in his “ Studies in Fossil 
