DRUPACEiE 399 



plums are first cleaned, and their skins ruptured to permit of 

 more rapid drying. Usually, they are dipped into boiling 

 water or hot lye, which not only cleans but also cracks the 

 skin. They are then dried in the open sun, or in drying 

 sheds where artificial heat may be utiHzed. After drying, 

 the prunes are allowed to "sweat" for two or three weeks. 

 They are then graded and "glossed" or finished by heating 

 in steam or immersing in salted boiling water, glycerine or 

 fruit juice. This gives the surface of the prunes a shiny 

 appearance, and also steriHzes the exterior. 



3. Peridrigon Plums. — This is a prune plum grown only 

 in France. 



4. Yellow Egg Plums. — The fruit of these is large, in fact 

 the largest of plums, long-oval, and has a yellow or purple 

 skin, and yellow flesh. Well-known varieties are Yellow 

 Egg, Red Magnum Bonum, Golden Drop, and Monroe. 



5. Imperatrice Plums. — These are medium-sized, dark 

 blue plums, with thick skin, firm flesh, and clinging stones. 

 Such varieties as Ickwor^h, Arch Duke, Monarch, Shipper, 

 Arctic, etc., belong to this group. 



6. Lombard Plums. — This group includes the reddish or 

 mottled varieties of Domestic plums. Lombard, Bradshaw, 

 Victoria, Pond, and Duane are well-known varieties. 



Primus insititia. — This is a small tree not over 25 feet high 

 with small ovate or obovate, finely toothed leaves which are 

 usually glandular; both surfaces of the leaves are sHghtly 

 hairy. The flowers are usually in lateral, umbellate clusters. 

 The fruit is globular or oval, small, usually bluish black or 

 golden yellow, and has yellow flesh, and a chnging or free 

 stone. 



Varieties of this species are hardy and thrifty. The species 

 has been in cultivation over 2,000 years, but in all that time 

 has shown but little variation. Insititia plums rank second 



