Possible Existence of a Lattice- Work Fern Stem. 211 
interesting exhibition had also been arranged by the Agricultural 
Department in Pretoria, of the various kinds of crops produced 
in the Transvaal—fruits, cereals, cotton, tobacco, etc., etc. 
On Friday Mr. Burtt-Davy organized a most successful botanical 
excursion to the Magaliesberg Mountains. Though, in consequence 
of the long winter drought, most of the vegetation was brown and 
dry, many plants were in fruit, and some in flower. The most 
striking feature, however, and the primary object of the expedition 
was the famous “ Wonderboom,” a remarkable specimen of 
Ficus cordata. Originally a single tree, the plant has gradually 
travelled outwards by the rooting of decumbent branches, until it 
has become quite an extensive grove of separate trees. After an 
at fresco lunch, which the local Committee had kindly provided for 
us, the President and Mr. Burtt-Davy energetically spent the 
afternoon in surveying and mapping the entire grove formed by 
the “ Wonderboom.” 
In addition to the set excursions, the members of Section K 
had many other opportunities of seeing something of the various 
types of vegetation characterising the different districts which were 
passed through during the tour. 
Of the kindness and hospitality with which we were every¬ 
where received, and which made the tour almost resemble a royal 
progress through South Africa, much has been written elsewhere. 
For the rest, though it has been suggested that the trip partook 
somewhat of the nature of a huge excursion, yet I think that the 
botanical members at least, of those who visited South Africa, are 
agreed that, for once in a way, it was well for the British 
Association to go further afield, and to explore “ fresh woods and 
pastures new.” 
R.H.Y. 
ON THE POSSIBLE EXISTENCE OF A FERN STEM 
HAVING THE FORM OF A LATTICE-WORK TUBE. 
By D. T. Gwynne-Vaughan. 
N most Polypodiaceae the vascular system of the stem has the 
form of a tubular lattice-work imbedded in a matrix of ground- 
tissue, and lying about half way between the axis of the stem and 
the periphery. In the light of recent researches it may be safely 
