24 MANUAL OF FRUIT DISEASES 
available. Not infrequently, however, growers state dogmati- 
cally that 50 per cent or more of their crop is affected. Rarely 
is a crop entirely lost; the fruits are not reduced to absolute 
worthlessness although in severe cases an apple affected with 
bitter-pit, or stippen, is éxtremely objectionable. From the 
standpoint of losses through reduced quality, the past history 
of the disease indicates clearly that stippen ranks high among 
the most important apple diseases of the world. In New York 
state, at least during certain years, the disease is the most serious 
of all apple troubles. f 
Although pears and quinces are known to be affected, yet 
the apple is by far the most seriously injured. It would not 
be safe to say that any variety of apple in the United States is 
immune to bitter-pit. Observations and records show, how- 
ever, that the Baldwin, above all others, is the most susceptible 
variety grown in North America. Many growers, in fact, have 
come to believe that stippen is a disease peculiar to this variety, 
whence the name Baldwin-spot. But this name is objection- 
able since the Baldwin is liable to other spot diseases of the 
fruit. Other varieties prominent in American apple-culture 
that are commonly affected with stippen are Northern Spy, 
Rhode Island and Tompkins King. It is a noteworthy fact 
that the disease under consideration affects most commonly, 
and often to a grave extent, some of the most valuable com- 
mercial varieties, while, as intimated above, a number of other 
varieties are subject to it. 
Like many other diseases of plants, stippen was known to 
growers long before’ it was the subject of published writings. 
There are good grounds for believing that the trouble may have 
existed in the apple from the time when it was first generally 
cultivated. In 1869 a pitting of apples was described in Ger- 
man literature. In that country it is now called Stippen, 
Stippflecke, and Stippigwerden, all of these names referring to 
a pitting or stippling. In 1886 it was reported from Australia 
