occurs, and abundance of moisture is supplied, there tli'e spotting is very 

 prevalent. One very important suggestion made by Quinn is tbat of the 

 possible influence exerted by the stock in the scion, for he points out that 

 nearly all Australian apple trees are grafted on Northern Spy stocks in 

 order to resist the attacks of the American blight or woolly aphis, and 

 it is well known that " the fruits of the Northern Spy are notoriously 

 affected by the ' bitter-pit.' " In support of this, Quinn brings forward 

 the comparative immunity of Tasmanian apples to bitter-pit, which he 

 thinks may be due to the fact that they are on their seedhng stocks, or 

 that the vitality of these stocks may be so impaired by the suctorial action 

 of the woolly aphis. 



Massee (13) in 1906 describes the disease as found in a sample of Cape 

 apples sent to Kew for examination. Massee examined the spots and 

 was of opinion that the spotting was due to the fact that the fruit had 

 been subjected to too high a temperature at the period of ripening, and 

 that the cells were killed by fermentation. 



Gussow (14) in 1906 reports the occurrence- of the disease in apples 

 grown in Worcestershire in England. His examination of the spots 

 revealed the fact that the cells in the diseased areas were larger than the 

 normal cells, and that the cell walls were thickened and dark coloured. 

 Abundance of starch grains were also noted as Uning the diseased cells 

 Gussow points out that Sorauer has observed that the disease was very 

 prevalent on the Continent in 1904, which happened to be a very dry 

 season. He also draws attention to the fact that an unusually dry summer 

 was experienced in Worcestershire when the injury appeared th^e, and 

 on these grounds accepts Sorauer's interpretation of the disease, that it 

 is brought about through the want of water not being able to supply the 

 necessary sap for the development of the fruit, " so that some groups of 

 cells, deprived of their food, become exhausted." 



Farmer (15) in 1907 gives a short note on his acquaintance with the 

 spot trouble. The presence of starch in the afiected cells appears to him 

 to be of great interest, and he thinks rather points to the action of the 

 diastase being locally inhibited. He is of opinion that the disease is due 

 to " obscure physiological causes, which can only be investigated on the 

 spot." 



McAlpine (16) in 1907 in his report on the disease in Australia says : 

 " With regard to bitter-pit, the effect of various manures on this condition 

 has been tried for a number of years, and while none have proved perfectly 

 satisfactory, it has generally been found that a complete manure, con- 

 taining nitrogen, phosphoric acid, and potash, aggravates the disease. 

 In some experiments carried out last year on the Bismarck variety, the 

 appUcation of dissolved bones containing nitrogen and phosphoric acid 

 only seemed to give the best result." 



Brooks (17) in 1908 in a paper entitled " The Fruit Spot of Apples," 

 describes two distinct troubles found in New Hampshire apples, which 

 he distinguishes as the fruit pit of apples and the fruit spot of apples 

 respectively. 



