TRANSACTIONS OF SECTION K. 921 
4, The Sand Dunes between Deal and Sandwich, with Remarks on the Flora 
of the Districts. Ly G. Dowker, F.G.S. 
The author in this paper gave an account of the formation of the dunes and 
mud banks, claiming for them the reclamation of the large tract of sand from the 
sea, mostly since the Roman occupation of Britain. He referred to the Acts of 
Parliament passed prohibiting the destruction of the mat grass, which contributed 
so largely to the preservation of the hills, and lamented that nothing was done to 
prevent the wholesale gathering of sea holly by men who ruthlessly destroyed 
it by taking it away to sell. He recounted his long experience and knowledge of 
the district, dating back to his schoolboy days with the Rev. J. Layton, a distin- 
guished botanist of Sandwich. He particularised the following rare plants as 
denizens of the hills: Allium vineale and compactum, Poa bulbosa, Hippophae 
rhamnoides, Silene conica, Orobanche caryophyllacea, Lepidium latifolium, and on 
the salt marshes, Atripler pedunculata, Frankenia levis, Aster Tripolium, and 
Polypogon monspeliensis. ‘The author added a list of over 300 species of flowering 
plants to be met with in the district. 
5. The Research Laboratory in the Royal Botanic Garden, Peradeniya, 
Ceylon. By J. C. Wis. 
6. Report on Fertilisation in the Pheophycece. See Reports, p. 610. 
7. Report on Experimental Investigation of Assimilation in Plants. 
See Reports, p. 611. 
FRIDAY, SEPTEMBER 15. 
The following Papers were read :— 
1. On White-Rot—a Bacterial Disease—of the Turnip. 
By Professor M. C. Porrrr, 
The author has found in the early autumn numerous turnips, whose roots, when 
fully grown, have become completely rotten. The rotten portion presents a white 
glazy appearance, and the tissues are reduced to a soft pulpy condition; the cell- 
walls are much swollen, faintly stratified, and separate from each other along the 
middle lamella, The decaying mass is infested with bacteria, but the most careful 
microscopic search has failed to detect any fungoid hyphe, and no fungi have 
appeared in the experimental cultures. 
The rottenness can be readily introduced into a sound root by inoculation at a 
wounded surface; from this point the decay spreads rapidly through the root, the 
leaves gradually turn yellow, and in about fourteen days the entire plant has 
succumbed. 
Among the bacteria found in the rotten mass one has been isolated, which, 
when sown from a pure culture on to turnips, under sterile conditions, induces all 
the characteristic effects of the ‘ white-rot.’ The liquid expressed from the pulp 
of one of these cultivations, when passed through a Pasteur-Chamberland filter, 
yields a clear light yellow filtrate, which was found to have the same powerful 
action upon the living cells of the turnip, causing the swelling of the wall and the 
‘separation of the cells by the dissolution of the middle lamella. This action was 
destroyed by boiling. When diluted with four to five volumes of alcohol, the 
extract yields a copious flocculent precipitate; the precipitate was dried and 
