DISEASED CONDITION OF PLANTS 51 
mottled patch, and the entire leaf may become bronze 
in colour or may develop bronze spots surrounded by a 
yellow zone. The affected leaves soon drop and spoil 
the appearance and health of the plant. Generally the 
disease appears on new branches below the place where 
the blooms have been removed. It is most prevalent 
on young plants, and especially those which have been 
forced too rapidly. Over-feeding appears to be an 
important factor in connexion with the disease. 
The dropping of flower buds is an important malady 
closely related to malnutrition. The flower bud appears 
in due course, turns yellow, and drops off the peduncle 
or stalk. In some cases the cause may be of fungoid 
origin, but generally it is due to an unbalanced food 
supply. Thus the tomato and sweet-pea both drop their 
flowers when there is an excess of available nitrogen in 
the soil, which causes them to grow too rapidly. The 
sweet-pea also drops its bloom in starved soil, and hot, 
dry weather may cause tomato flowers to drop. 
An excess of nitrogen and potash has a distinctly 
harmful effect upon carnations, as is well known to 
growers of this plant. The former produces weak flowers 
liable to scorch and attack by Botrytis. Such blossoms > 
are malformed and frequently do not open. An excess 
of potash salts produces a hardening and wrinkling of 
the petals, and at times the margins turn brown and 
wither. The buds do not open properly and are dis- 
torted. The plants become stunted and the leaf tips 
turn yellow and die. Occasionally carnation flowers 
split prior to opening; and while the cause is yet 
obscure, there are indications that unsuitable manuring 
is an important factor. 
If the tomato is overfed in the early stages of its 
growth and starved at a later period it develops a hollow 
stem, and becomes physiologically weak and liable to 
disease. Similar symptoms develop in the tops of 
tomato plants which have borne an exceptionally heavy 
crop on the bottom trusses; such plants are physio- 
