4 BULLETIN 714, U. S. DEPARTMENT OF AGRICULTURE. 
the Early Black and the Howe varieties were kept in containers of 
known humidity, using a method already described by one of the 
writers (13), no direct relation was found between the humidity of 
the air and the amount of rot of the fruit. Berries kept as well in 
very moist air as in drier air unless they were actually wet. 
NATURAL RIPENING PROCESSES. 
Like other fruits, the cranberry when picked is a living organism, 
carrying on its vital activities, which may be referred to in general 
as ripening processes. Of these processes one of the most important 
is respiration. Under normal conditions the respiration of a fruit 
is marked by taking in oxygen and giving off carbon dioxid. In this 
process the living matter of the fruit is broken down and the berry 
gradually loses weight. If continued long enough this process would 
end in the destruction of the berry. It has been demonstrated that 
respiration goes on more rapidly at high than at low temperatures; 
consequently, the cooler the berries can be kept without freezing the 
longer they will live and the better will be their condition. 
SMOTHERING. 
CONDITIONS WHICH CAUSE SMOTHERING. 
In a paper published with the report of the Massachusetts 
Cranberry Station for 1916 (11) the writers called attention to 
the spoilage of cranberries caused by insufficient ventilation. As 
pointed out at that time, cranberries kept in tight cans or in an 
atmosphere of carbon dioxid lose their crispness and bright color, 
become dull red and flaccid, and taste bitter. Since this kind of 
spoilage is apparently caused by conditions which check normal 
respiration, the writers designate it as smothering. Experience has 
shown that whenever cranberries of good keeping quality are cov- 
ered with some inert gas, such as carbon dioxid, buried for some 
time in a big pile of berries, shut up in a tight container, kept under 
water, or subjected to other conditions which prevent normal res- 
piration, smothering occurs. The exact causes of this spoilage, as 
well as the nature of the changes brought about in the fruit, are nosv 
the subject of investigation by Prof. F. W. Morse, of the Massa- 
chusetts Agricultural Experiment Station. 
When berries are under water or under carbon dioxid, death due 
to smothering occurs in a short time, often in one to two weeks, 
whereas in tight containers or in large piles it results so slowly that 
if the berries are of inferior keeping quality fungous rot may de- 
stroy them before the effect of smothering appears. In case rot- 
producing fungi are present, they develop rapidly on the weakened 
berries, and a mass of rotten fruit results. 
