SCIENTIFIC COMMITTEE, APRIL 18. 
xxix 
Hyacinth Stem and Leaves groiving doivnivards . — Mr. Henslow 
showed a plant the bulb of which had been accidentally inserted upside 
down. The roots had grown normally downwards ; but the shoot, instead 
of turning upward towards the light, had also grown vertically downwards, 
the greatest energy of growth being at the base of the leaves. It subse- 
quently elevated the bulb into the air, removing all the roots from the 
soil, and continued to grow solely at the expense of the nourishment 
contained in the bulb. The flower-stalk, closely invested by the leaves, 
was 7 in. in length. 
Carnations attacked by Acarus. — Mr. Michael reported upon the 
specimens sent to the last meeting as follows : — " The Carnation pest is 
a Tarsonymus. All this genus are destructive and difficult to eradicate, 
in consequence of their leaf- and stalk-mining habits." 
Diseased Carnations. — Dr. W. (1. Smith, Leeds, reports as follows : — 
" On the Carnations sent none of the fungi usually present was found, e.g. 
rust, leaf-spot, fairy ring-spot. The symptoms presented are those of the 
disease known as * bacteriosis.' This is the name given by Arthur and 
Bolley (Purdue Univ. Agric. Exp. Station, Bulletin, 59, 1896), because 
they ascribed the disease to the action of a Bacterium (B. dianthi). 
They were able to infect healthy plants with cultures from diseased 
specimens. A Belgian investigator, Paul Nypels, published in 1898 
{Notes Pathologiques) some observations on the disease, which point to 
some other agent than bacteria as the primary cause. Other workers 
also hold this view. The disease is well known, and very destructive in 
the indoor cultivation of Carnations in the United States and in Belgium. 
The conditions favourable to it are overcrowding, defective ventilation, 
and the effect of moisture on the foliage, due to overhead watering. 
Prevention is evident, except for the last item mentioned ; but overhead 
watering must be reduced as much as possible. The structure of the 
Carnation leaf indicates a plant suited to a dry, open situation, like our 
native Dianthus, on rocks, old walls, and open pastures. In indoor 
cultivation means must be adopted to prevent too frequent wetting of the 
foliage. This has been done by some growers in America, as described 
by Arthur and Bolley. Pieces of wire netting bent into a /\ shape are 
placed between the rows of plants, so as to keep the lower leaves clear of 
the stages. The water is then applied by means of a hose directed into 
the and the water is distributed to the roots by a nozzle, delivering on 
both sides. Arthur and Bolley give illustrations in the Purdue Bulletin 
The method has been successful against this and other diseases of indoor 
Carnations. Where this disease has already shown itself it may be 
checked by spraying the foliage with Bordeaux mixture." 
Vines Malformed. — Mr. G. Wythes, of Syon House, sent branches of 
Vines with malformed flowering bunches, supposed to be due to fog, but 
they presented a not uncommon condition of being tendrils bearing 
abortive buds. As Darwin, and many others before him, point out, Vine 
tendrils are homologous with flowering shoots, and such transitional 
states between simple tendrils and bud-bearing ones occur on all Vines, 
and have nothing to do with external climatic conditions. 
Effect of Lightning on an Oak. — A specimen received from D)*. Plow- 
right, of Lynn, showed how Oak-wood is sometimes torn into longitudinal 
