SCIENTIFIC COMMITTEE, JANUARY 9. 
XXV 
SCIENTIFIC COMMITTEE. 
January 9, 1900. 
Dr. M. T. Masters, F.R.S-, in the Chair, and five members present. 
Horse-radish attacked by BhizoglypJms. — Roots of Horse-radish and 
Lily of the Valley, attacked by this mite, were received from Abbey, 
of Avery Hill, Eltham, who forwarded a long list of plants likewise 
attacked. Mr. Michael observed that it is a subterranean species, and that 
although it prefers bulbs it is very injurious to many— indeed, most other 
plants with fleshy roots, though it may not thrive equally well upon 
them all. As a remedy, Dr. Miiller suggested lime and sugar or treacle, 
as being better and stronger than lime-water, as well as more persistent in 
its action. Mr. Michael also observed that heat, such as boiling water, 
was destructive, but the mite resisted chemicals to a remarkable degree. 
With regard to its hfe history, it passes through several stages, com- 
mencing with the egg ; this gives rise to a hexapod lava, then to the 
nymph, a very active octopod. After a new change of skin in a large 
number of cases, but not in all, there emerges —without any discoverable 
cause — a being totally unlike the preceding, formerly known as Hypopus, 
having been thought to be a quite different genus. This has a soft body 
internally, but covered with a hard and usually chitinous integument. 
Its mouth organs are rudimentary, and it probably does not feed. It is 
provided with discs, by means of which it adheres to insects such as ants, 
bees, beetles, &c., and to other small moving creatures. These it utilises 
as means of migration, chnging to them, but without being parasitic. 
As soon as a suitable environment is met with the mite changes back into 
the last nymphal stage, and then proceeds to pass into the adult male or 
female condition. It may attack plants in all stages, except that of the 
migratory Hypopus. The Hypopus is practically impervious to chemicals, 
and can endure without injury exposure to heat and drought, which -would 
destroy the creature in any other stage. 
Apples injured by Hail. — Some fruit was received from Mr. Wood- 
ward, of Barham Court, Maidstone, which had received severe injuries 
from hailstones. But although the skin was cut through and the flesh 
exposed, this had dried up and so protected the interior, which had not 
at all decayed. The storm occurred on July 19, 1899. Mr. Michael 
observed that when birds plunge their beaks into Apples through thirst 
the injured spots almost invariably result in decay. 
Scientific Committee, February 13, 1900. 
Mr. Bennett-Poe in the Chair, and four members present. 
Elm-bark loith larvcB. — Mr. W. Brooks, of Weston-super-Mare, for- 
warded a piece of bark of an English Elm-tree, with the following 
observations : — The Elm-trees are attacked by an insect which is destroy- 
ing them. Some of the trees are fine, nearly 100 feet high, and in their 
prime ; others are smaller. The larger trees are attacked more especially 
