922 REPORT—1899, 
digested with a little water, and the solution, after filtration through the Pasteur- 
Chamberland filter, was also found to have the same effect upon the cell-walls, the 
action again being destroyed by boiling. The whole appearance of the sections 
corresponded exactly with those taken from turnips affected by the rot. The 
bacterium, therefore, secretes a cytase enzyme, which, in healthy living tissues, 
dissolves the middle lamella and causes the swelling of the cell-wall. The same 
enzyme is produced when the bacterium is grown in Koch’s bouillon. 
The bacterium has a single polar flagellum, and, adopting Migula’s classifica- 
tion, the author has ventured to describe it under the name Pseudomonas 
destructans, 
General Characteristics, 
Short rods about 3 long by *8u broad, with one polar flagellum. 
Rapidly liquefies gelatine, forming circular whitish colonies. 
Agar-agar, whitish glazy growth. 
Stab cultures grow along the track of the wire, rapidly forming a funnel. 
Aerobic. 
Parasitic on turnips, potatoes, carrots, but not beetroot, forming a cytase, 
Copious evolution of carbonic acid during the fermentation, 
Infection by P. destructans appears always to be introduced at a wound, and 
it is powerless to set up decay unless placed in contact with the parenchymatous 
cells of the cortex. Having gained an entrance, the organism penetrates the 
living tissues by means of the intercellular spaces, and by the action of the enzyme 
it breaks through the intercellular substance and traverses the middle lamella. 
Many of the intercellular spaces are crowded with bacteria, and in some sections 
they are found lying in the track of the middle lamella. 
2. On the Phosphorus-containing Elements in Yeast. 
By Harotp WaGER. 
3. On the Influence of the Temperature of Liquid Hydrogen on the Germi- 
native Power of Seeds. By Sir Witu1aM Tuisetton-Dyerr, K.C.ILG., 
PRS. 
Sir William Thiselton-Dyer described some experiments made by Professor 
Dewar on the influence of the temperature of liquid hydrogen on the germinative 
power of seeds. The most important was one in which five kinds of seeds, varying 
in size and conformation, were immersed for six hours in liquid hydrogen. The 
temperature to which they were cooled was —453° F. below melting ice. They 
were subsequently sown at Kew, and germinated readily without exception. 
The bearing of the experiments on the accepted conception of protoplasm gave 
rise to some discussion. Protoplasm is conceived to consist of physiological 
molecules, the properties of which cannot be explained with our present knowledge 
of either physics or chemistry. They are in a state of constant kinetic energy, 
based upon equally continued metabolic change. But if it is admitted that the 
latter is impossible at very low temperatures the former must cease and the evi- 
dence of life disappears. The physiological molecule becomes purely static; its 
energy is wholly potential, and, in fact, it becomes, as Professor Casimir de Candolle 
has pointed out, analogous to an explosive. 
4. On a Horn-destroying Fungus. By Professor MarsHaLt Warp, F.R.S. 
