ENEMIES. 133 
arrested, and the basal part swollen and contorted. On examining a 
portion of the diseased leaf, especially where decay has set in, eel- 
worms are found, and in further putrefaction the ova or eggs with 
young wormlets or larvae are discovered. With the decay of the plant 
or part diseased the young wormlets pass into the soil, and live upon 
decayed or organic matter. Infection, therefore, is from the soil, 
possibly not attacking plants where the soil and other conditions are 
favourable for healthy growth. The eelworm usually associated 
with fuzzy Carnations is the stem eelworm, Tylenchus devastatrix. 
In many cases the foliage is not affected other than by impoverish- 
ment, but the stem at the collar and more or less downwards is 
considerably enlarged and swollen. In this nodosity, mostly cellular 
tissue somewhat decayed, may be found nematoid worms of a much 
shorter and blunter conformation than those usually found in 
diseased leaves above ground. These are rootstem eelworm, T. 
obtusus. In some cases the much longer and narrower stem eelworm 
cuts off the supplies of nourishment, and the plant sooner or later 
collapses. 
Burning the affected plants is the only means of extirpating eel- 
worm. Infested plants, whether fuzzy or “gouty,” are not curable, 
for the nematodes are lodged in the tissues. In the soil the pests are 
readily destroyed by caustic substances such as lime, and also by 
dressings of kainit, the latter being used with basic cinder phosphate. 
The materials for potting should be in a thoroughly sweetened 
condition. 
VI.—The Carnation Maggot (Hylemyia nigrescens). 
This pest is one of the most troublesome and destructive foes of 
the Carnation. It attacks all varieties, though some are freer from 
it than others. The worst affected outdoors are the common Clove 
and seedlings, also gross layers, and indoors Souvenir de la 
Malmaison, likewise rose Flakes and pink and purple Bizarres. The 
younger and softer the growth, whether due to the habit of the 
variety or to gross culture, the more likely is the plant to be selected 
by the Carnation fly for depositing its eggs; hence the disease is 
mainly observable in seedlings or layers, and after the plant has 
attained a certain age it appears to enjoy a comparative immunity 
from attack. 
The fly resembles a house fly in general appearance, but is 
smaller. I[t is two winged, grey or blackish ; the back is indistinctly 
striped, the abdomen hairy. It sometimes deposits the eggs in the 
leaves, raising a whitish brown patch like a blister; and in such 
cases the affected parts have merely to be cut off, making sure that 
the maggot is in the part, and destroyed. Butin some cases the eggs 
are deposited in the axils of the leaves, or on the stem, and the 
maggot is developed there without previous warning, and the heart 
of the plant is eaten out before the presence of the enemy is detected. 
This is indicated by the centre of the plant or shoot having a pallid, 
sickly appearance ; after a time the heart drops completely out. In 
