250 
The London Botanical Society. 
The observation, however, of the author which, in our opinion, 
crowns all in adding weight to the already strong evidence in favour 
of the Medullosean descent of the Cycadaceae, is that of the occur¬ 
rence in the hypocotyl of Encephalartos Barteri (seen, we believe, 
for the first time in the history of the study of modern Cycads) of 
a central cylinder consisting, not of the usual collateral vascular 
structure, but of a g roup of three or four concentric strands or stelcs r 
quite comparable to the group of steles which constitute the vas¬ 
cular tissue of the stem of Medullosa anglica as described by Scott. 
We have always maintained and believed, in contradistinction to- 
the opinion of Scott (who has ever held to the monostelic derivation 
of the Cycadean central cylinder), that in all Cycads the central 
vascular ring of collateral strands has been derived by descent from 
a cylinder of concentrically-constructed steles, such as obtains in the 
Medulloseae, by means of the extinction of the inner inverted 
portion of such steles. This view is completely endorsed and sup¬ 
ported by Dr. Matte. It should be remembered that it is precisely 
in the seedling plant, and especially in its hypocotyledonary regiou 
that we might expect the appearance of ancestral traits. If the 
structure occurring in the hypocotyl of Encephalartos Dartcri 
represent indeed, as we firmly believe, the normal adult structure of 
the stem in the ancestors of this genus; then it follows that pre¬ 
cisely the same must be true in the case of all other Cycads, 
whether mono- or pleio cylindric. 
In conclusion, we should like to congratulate the author on an 
original and illuminating contribution to our knowledge of the 
structure and affinities of this remarkable group of plants. 
Kew, 
November 1st, 1904. 
W. C. WORSDELL. 
THE LONDON BOTANICAL SOCIETY. 
| ^HE forty-ninth Meeting of this Society was held in the 
Biological Lecture Room of the Royal College of Science at 
4.30. p.m., on Monday the 28th ult., Dr. D. H. Scott, F.R.S. in the 
Chair. 
Dr. F. E. Fritsch read a paper on the structure of the invest¬ 
ment in Cyanophyceae. It was shown that within the external 
mucilaginous envelope of an Anabaena two membranes could be 
distinguished around each cell, as soon as the cells began to pass 
