16 



BITTER PIT INVESTIGATION. 



In this, as in other diseases, it is customary for the average orchardist to observe only 

 external appearances, and not go beneath the surface for an explanation. But conclusive proof 

 is given of the internal origin of the disease when an affected apple is cut across, and the continuous 

 brown spongy line is seen beneath the green skin which is perfectly formed on the outside (Figs. 33, 

 36, 38). 



The only reference I can find to this disease elsewhere than in Australia is by R. E. Smith 

 (82) in California, where it is described and figured under the name of the " Hollow Apple." 



" A peculiar condition found in one or two instances. The affected fruit is sunken in on 

 one side, and has a mis-shapen appearance. On cutting through the apple, large hollow cavities 

 are found, corresponding to the sunken areas on the surface, due apparently to some injury while 

 the fruit was small." 



CHEMICAL DIFFERENCES BETWEEN SOUND AND CRINKLED. 



In order to test the chemical difference, if any, between the crinkled and sound from the same 

 tree, specimens of Five Crown and Annie Elizabeth were submitted to Mr. Scott, the Agricultural 

 Chemist. The apples chosen were as nearly as possible of the same size and generally similar. The 

 following is the result : — 



Table III. — Analysis of Clean and Crinkled Apples. 





" Five Crown " 



" Annie Elizabeth " 





(Healesvilie). 



(Burnley Gardens). 





Clean. 



Crinkled. 



Clean. 



Crinkled. 





Per cent. 



- 



Per cent. 







Per cent. 



Per cent. 



Moisture . . 



83-81 



83-06 



84-33 



85-06 



Acidity (as Malic Acid) 



•576 



'576 



•858 



•610 



Total Sugar — percentage of juice (as dextrose) . . 



12-50 



13-41 



11-28 



10-99 



The amount of moisture, the acidity, and the total sugar contents were the points chosen for 

 comparison. As regards moisture, chemical analysis showed less in the crinkled Five Crown and 

 more in the Annie Elizabeth apple. In acidity, there was practically no difference, although in 

 the Annie Elizabeth there was slightly less ; and, as regards total sugar, there was a little more in 

 the Five Crowns and a little less in the Annie Elizabeth apples. So that no general conclusions can 

 be drawn from the results, although it would have been more satisfactory to have analyzed only 

 the crinkled tissue and not the entire apple for comparison. 



VI— AN "OBSCURE DISEASE " OF THE APPLE. 



In 1892, Dr. Cobb (15), then Vegetable Pathologist to the Department of Agriculture, New 

 South Wales, referred to an " obscure disease " which rendered the apples worthless. They were 

 of irregular growth, hard, and often bitter. Then, again, in 1897 (17), he referred to it under the 

 heading of " Cause of an important Apple Disease," and attributed it to the woolly aphis. He 

 found this insect on the apples, and sometimes a few in the passage leading to the core, "and he came 

 to the conclusion that just as they cause unsightly malformations on the roots and limbs, so may 

 they affect the fruit and cause this deformity. The woolly aphis is often found on the apple, 



