ACIPENSERID^E — THE STURGEONS 23 



given in 1898 as about 4,000,000 lb annually. The smoked 

 flesh usually keeps only from one to two weeks. It is not kept 

 in cold storage because of its tendency to mold. Sturgeon is 

 canned on a small scale, and the roe, preserved in brine and 

 sold in tight packages under the name of caviar, is an expensive 

 food product highly relished by man}-. The method of pre- 

 paring caviar is simple, the first essential being to work the eggs 

 lose from the membranous tissue in which they are embedded. 

 When once separated they are mixed with Luneburg salt, with a 

 small addition of one of the ordinary preservatives. The eggs 

 are then sieved and drained for 12 to 20 hours, after which they 

 are ready for packing. Caviar is usually packed in small oaken 

 kegs, although it is also sealed in small tins for the retail trade. 

 The Russian output amounts to about 8,000,000 lb annuahY, 

 most of it prepared on the Volga and the Caspian. The Amer- 

 ican product is about 300,000 lb annually (1898), about % of it 

 being exported. Sturgeon bladders are used in the manufacture 

 of isinglass, and oil is made from the offal and softer parts. 

 Sturgeon skin has been somewhat used of late for an ornamental 

 leather. The skin is exceptionally durable and has been used 

 for laces for mill-belts. 



Owing to their great commerical importance, the artificial 

 propagation of sturgeon has long been a subject of more or less 

 nterest in this country and in Europe. Up to the present time, 

 however, although the artificial fertilization of the eggs and the 

 successful hatching of the young has been accomplished experi- 

 mentally*, it has not been practiced on a large scale anywhere, 

 the difficulty of obtaining ripe roe and milt at the same time, the 

 adhesiveness of the eggs and their tendency to mold, and the 

 difficulty of finding food for the young (which live on micro- 

 scopic organisms), having proved serious obstacles. It has, 

 however, been the opinion of all who have investigated the sub- 

 ject that if artificial culture were once undertaken, these diffi- 

 culties would soon be greatly diminished. It may be said that 

 the number of eggs produced by the Atlantic sturgeon is from 

 1,000,000 to 2,500,000 to a single adult female— a fact of much 

 importance to its artificial culture. 



* The eggs were fertilized dry by Dean (Bull. U. S. Fish Coram., 1893, p. 335), and then 

 put into water and allowed to adhere in a single layer to a sheet of cloth stretched over a frame. 

 They were hatched out in the current of the river, the loss by fungus being only 5 per cent. 

 Artificial propagation was tried by the Germans in 1888 with fair success, and in America by 

 Ryder (1889), who lost most of his eggs. Some success has been more recently obtained by the 

 Russian government, operating on the Ural. 



