LIABLE AND NON-LIABLE VARIETIES COMPARED AND CONTRASTED. 25 



If we take the total amount of growth in length made by the Yates apple during the season, and 

 examine the proportions for the different periods of spring, summer and autumn, it is found that in 

 the spring months the growth was f f , in the summer months -?, and in the autumn months / K . Over 

 one-half of the total growth in length was made in the spring months. 



If the growth in diameter is considered similarly, it is found that in the spring months it 

 was , in summer f, and in autumn T 4 n . So that the growth in breadth in the spring was also over 

 one-half the total. 



In the accompanying table the rate and amount of growth is shown at weekly intervals. 



TABLE XIII. AMOUNT OF GROWTH AT STATED INTERVALS IN YATES AND CLEOPATRA APPLES 

 EXPRESSED IN THIRTY -TWO PARTS OF AN INCH. 



Date. 



February 2 

 8 

 15 

 22 

 1 

 8 

 15 

 22 

 27 

 5 

 9 

 12 

 19 

 26 



March 



April 



Rainfall 

 between 



pates. 



inches. 



09 



06 

 36 



02 

 04 

 02 



31 



46 

 97 

 13 



RELATION BETWEEN THE NATURE OF THE LEAF AND BITTER PIT. 



The leaves of apple trees are very varied in their character, and yet they are so characteristic 

 in different varieties, that they often serve to identify the particular sort. They are apt to vary in 

 different portions of the individual tree and typical examples are to be looked for on the upright 

 shoots freely exposed to sun and air. Their size and shape, colour and texture, upper and under 

 surface are all points worthy of note, but we will confine our attention to those characters which have 

 a direct effect upon the transpiration. 



Since the leaves are the chief organs of transpiration, they have received special attention, and 

 any points in their structure which favour or retard it, will have an influence upon the amount of 

 water given off, relatively to the water supply. The exit of water in the form of vapour is regulated 

 by means of openings in the skin, known as stomata. In the case of the apple leaf, as in most leaves, 

 they are entirely absent from the upper surface, and are distributed over the lower surface to the 

 number of about 246 per square millimetre. Associated with these on the lower surface, there is 

 usually a pubescence or downiness, which may be short or long, fine or coarse, and may be often 

 rubbed off as a woolly or downy covering. 



This downy covering consists of densely-packed dry hairs, and brings about a reduction in the 

 transpiration, because the air entangled in the meshes of the hairs is stationary, and transpiration 

 is therefore less active than it would be if the air were continually renewed. 



This pubescence is more prominent, as a rule, in the young leaves, and it was observed that 

 while the leaf of Yates is smooth on the under surface, that of Cleopatra is very decidedly downy. 

 It is evident that if transpiration is retarded in the leaves, there will be a greater amount of moisture 

 conveyed to the fruits. 



