PROCEEDINGS. LIX 



flesh sent to China as food, the shells being sent to England and 

 elsewhere for pearl. Of unspecified shells about ^400,000 worth 

 are exported, the total value of invertebrate products being over 

 ^570,000. Among other articles specified were canned goods. 

 The value of canned salmon exported was over ^2,300,000. The 

 total value of fish products was about ^4,000,000. 



Prof. C. V. Riley made a communication On the Rust of 

 Oranges. 



The nature of this rust had been carefully studied by the author 

 and also by one of his assistants, Mr. H. G. Hubbard, at Crescent 

 City, Fla. It has always been known and has always given con- 

 cern. It varies from a more or less pronounced stain beneath the 

 cuticle to a rough, deep brown incrustation. When heavily coated, 

 the surface is chapped like that of a russet apple. It may be first 

 noticed when the fruit is small, or one-third grown (early summer). 

 It rapidly increases in August and September, when the fruit is full 

 grown, and is most noticed when the fruit begins to color, though 

 there is no increase, but rather a decrease, after that time. 



Rusts are mostly due to fungi, but there is nothing of this kind 

 about the orange rust. The oil cells are depleted and the epithelial 

 cells clogged with brownish resin. The surface is fissured and the 

 rind shrinks, toughens, and loses essential oil. Carefully examined, 

 a rusty orange will be found covered with cast mite skins — thick in 

 summer or fall, less noticeable in winter. The mites themselves 

 will be found on the non-rusted fruit and all over the tree in spring 

 and summer. They are so minute as to be scarcely noticeable 

 singly, but collectively give the green leaf and fruit the appearance 

 of being sprinkled with fine golden dust. Pine pollen is often mis- 

 taken for them, and they, in turn, for the pollen. 



The attacks of the mite are always followed by rust on the fruit, 

 but on the leaves the mites produce only a dull, tarnished appear- 

 ance, contrasting with the polish of the healthy leaf, and a sure 

 indication of depredation even after the mites have left. The 

 leaves look dry and dusty, with slight loss of color, as from drouth. 

 When the foliage of the tree is bright the oranges are bright. The 

 living mites are not found on rusty oranges ; they quit both fruit 

 and leaf, and wander to fresh fields when the oil is depleted or the 

 surface too hardened for their beaks. 



