Arthur 8. Horne and Eleanor Violet Horne 187 



through varietal characteristics of the apples on which they occur: 

 conversely, spots of a somewhat similar category — brown spots, for 

 example — should not be held to indicate a likeness of origin, since a 

 brown colour is one of the commonest symptoms of a pathological 

 condition. 



Spots of different kinds may occur on tlu j same variety and even on 

 the same apple. There were on Lane's Prince Albeit, received from 

 Berkshire at the end of April, 1915, pale brown spots with a dark brown 

 centre; chocolate brown spots with a pale centre, and blackish spots 

 mottled with green; some spots were variously dotted, others not. On 

 other apples of this variety received at the same time, dendritic markings 

 were present on a pale brown ground, and in the same variety greenish 

 and purplish sunken blotches and dark brown spots with a pinkish red 

 border also occur. 



"Spotting" has been observed in about one hundred varieties of 

 apple, and occurs in a widely representative series of varieties — early, 

 mid-season and late, and whether culinary, dessert or exhibition — in- 

 cluding a number of sorts most prized in commerce. The varieties which 

 escape include hard-fleshed apples, notably the russets (Christmas 

 Pearmain, Worcester Pearmain, etc., with the exception of Hubbard's 

 Pearmain): the late pippins (Allen's Everlasting — a seedling from Stur- 

 mer Pippin, Fearn's Pippin, etc.); also, as far as observations of 1917-18 

 show, certain other varieties with crisp sub-acid flesh, such as Barnack 

 Beauty, Gloria Mundi, Belle Dubois. 



"Spotting" in relation to the lenticels. 



The surface of the apple is studded with numerous minute pale, 

 more or less stellate, apertures which are more conspicuous on some 

 varieties than others. These are usually referred to as lenticels 1 , although 

 they do not possess the typical structure of such organs. McAlpine 2 

 states that they are formed through rupture of the stomata as a result of 

 expansion as the apple increases in girth ; he gives a photographic repro- 

 duction of a pore showing the remains of a stoma (McAlpine, Plate XIV, 

 fig. 102). They take their origin therefore in the same way as lenticels. 



In a number of cases the spots originate at the lenticels. A careful 

 examination will show a complete series of stages from discoloured 

 lenticels to spots. In Wellington the smallest spots just encircle the 



1 The stomata are not all ruptured by the time the apple reaches maturity: stomata 

 were observed quite late in the season in a large specimen of an unknown variety. 



2 McAlpine. '"Bitter Pit Investigation," First Progress Report (1911-12), p. 40. 



