6 BITTER PIT INVESTIGATION. 



"crude sap" to its destination, with the healthy action of the leaves in supplying the "elaborated sap" 

 in due proportion to blend with the materials derived from the soil, and finally with the flower, which 

 is the necessary antecedent to the formation of the healthy and normal fruit, by means of proper 

 pollination. That this wide view is necessary for a proper understanding of the subject is seen in the 

 great variety of contributing factors which have been brought forward to account for the disease, 

 and most of them more or less applicable to different phases of it. 



Thus the late Dr. Rothera in his bio-chemical researches, in conjunction with myself, arrived at 

 the conclusion, after very elaborate experiment, that "starch metabolism and Pit are evidently closely 

 associated.'' Wherever metabolism is concerned, or the process of nutrition with the various chemical 

 changes involved in the process, then a wide field is opened up for exploration as to the cause of the 

 disordered nutrition. 



Again, it is said to be a disease of the vascular or conducting system, and no doubt the vessels 

 of the apple are involved in it. The disease begins in the neighbourhood of the vessels, which also 

 become discoloured, as well as the surrounding pulp-cells. 



But when it is said to be a constitutional disease, then the vast scope of the enquiry becomes 

 manifest. The real root of the matter lies in the weakening of the constitution of the apple, by the 

 efforts of successive generations of men to produce an enlarged, succulent, and palatable fruit. This 

 is gained at the expense of the vascular system (which is such an important feature of the fruit) and 

 a consequent softening of the fibre. When it is considered that all our cultivated apples are derived 

 from the small and sour Wild Crab, the improvement is a matter for congratulation, but at the same 

 time calls for the highest skill in remedying the defects arising from this interference with the inherent 

 vigour of the wild stock. 



The following Report consists largely of the results of continuous experiments, conducted during 

 a period of five years, and while the investigation is academic in the sense that it deals with principles, 

 it is also practical in the sense that it deals not only with the cause of the disease, but suggests measures 

 for preventing it in the oversea shipments of fruit and for minimi/Jug it in the fruit while growing on 

 the tree. 



The great lesson taught by this investigation, as a whole, is that if progress is to be made, know- 

 ledge increased, and the products of the soil brought to their highest perfection, it is by the experi- 

 mental method that such results are to be secured. 



