Anbury , Club-root , or Finger and Toe. 
337 
X;IOQO 
able to move about, changing its shape and pushing out from 
the margin one or more processes which pull the mass after 
them. A fine hair-like cilium also assists it to move in the 
water. The spore from which the speck of living jelly escaped 
agrees with the spores of other minute plants, but this active 
stage of the organism agrees so closely with the amoeba that the 
parasite and its allies are considered to be related to the animal 
as well as the vegetable kingdom, and have been named by 
De Bary, who has investigated their struc- 
ture and history. Mycetozoa , that is, in English, 
fungus-animal. 
This minute moving speck of naked pro- 
toplasm passes between the particles of the 
moist soil in search of a plant on which it can 
live. Like many other parasites it attacks only 
one kind of plant. The fungus causing the ri«. 2.- spores of the 
potato disease lives only on the potato and aZft\vo P fr™am^ba- 
one or two of its allies ; rust, mildew, smut, pi ke ;m Peck3 of proto " 
and ergot attack only cereals or other grasses. 
So this minute speck of living jelly passes by any roots that it 
may encounter in moving through the soil until it discovers 
those of some cruciferous plant. It attacks the turnip, cabbages 
of all kinds, Brussels sprouts, broccoli, cauliflower, kohl-rabi, 
swedes, also rape, and it has been observed on some wild plants 
of the same family, such as charlock, wallflower, candytuft, &c. 
No doubt many of these amoeboid specks perish in their 
journeyings through the soil, but the incalculable myriads of 
spores left by a crop of diseased turnips supply more than 
enough, after meeting all casualties, to attack the suitable roots 
within reach. And, lifted by the wind from the surface of a 
field, they are carried in the air, and spread the disease in fields 
where it was before unknown. 
The passage of the speck of protoplasm into the root of the 
turnip or cabbage has not yet been observed, but numerous 
experiments have shown that it does get in, and almost certainly 
the entrance is secured through the root-hairs. Just behind 
the growing points of all roots there are to be found a great 
number of minute hairs whose function it is to assist the root in 
drinking in the water and the substances dissolved in it required 
by the plant for its food. Passing in through one of these hairs, 
and finding its way into a cell in the root, it begins to live on 
the protoplasm contained in the cell, and speedily increases in 
size, pushing out the wall of the cell, until it attains so great a 
dimension that it can be easily seen by the naked eye. Portions 
of this growing mass of protoplasm pass into other cells, and 
