104 THE POPULAR SCIENCE MONTHLY. 



a cod-roe weighing seven pounds and three quarters, and found 

 the average was one hundred and forty eggs to the grain. This 

 gives 67,200 eggs to the ounce, so that in the whole mass of this 

 one cod-roe, allowing three quarters of a pound for skin, mem- 

 brane, etc., there were no less than 7,526,400 eggs. 



Caviare is the common name for a preparation of the dried 

 spawn or salted roe of fish. The black caviare is made from the 

 roe of sturgeon, and a single large fish will sometimes yield as 

 much as one hundred and twenty pounds of roe. A cheaper and 

 less prized red kind is obtained from the roe of the gray mullet, 

 and some of the carp species, which are common in the rivers and 

 on the shores of the Black Sea. It is of interest to Turkey and 

 the Levant trade only. 



Botargo is a preparation made on the coasts of the Mediterra- 

 nean, of the ovaries full of the mature eggs of the mullet (Mugil 

 cephalus). The eggs are salted, crushed, reduced to a paste, and 

 then dried in the sun. Sometimes spices or other ingredients are 

 added. Botargo is eaten like caviare. 



There is also a destruction by mankind of the ova or spawn of 

 the Crustacea — lobsters, crabs, and shrimps — which are carried 

 under their tail. The lobster produces from 25,000 to 40,000 eggs, 

 the crayfish upward of 100,000. As much as six ounces of eggs 

 can be taken off in May from a lobster weighing three to three 

 pounds and a half, and there are about 6,720 eggs in an ounce of 

 lobster spawn. The lobster is never so good as when in the con- 

 dition of a " berried hen." 



The eggs of some insects are eaten in Siam, Egypt, and Mexico, 

 but those most valuable commercially are the eggs of the silk- 

 moth. 



The trade in silk-worms' eggs from Japan has become an ex- 

 tensive and profitable one. In 1868 £1,000,000 was paid to Japan 

 by the "■ graineurs " of Europe for silk-worms' eggs. In 1869 two 

 million cards, costing on an average 12s. Gd. each, were sent to 

 Europe. In other years three millions of these cards, packed in 

 cases of about three hundred, thickly studded with these tiny 

 specks, have been shipped from Japan by the various steamers. 



In China and Japan the moths are placed to lay their eggs on 

 cardboard or thick paper, which they cover regularly and closely 

 with a secretion which glues them to the spot and acts as a pre- 

 servative from heat or other accidents. Hence the cards may be 

 transported many thousands of miles safely, in a ship with a prop- 

 erly regulated temperature, so as to prevent their hatching too 

 soon. They should be arranged, and the cards thickly covered, 

 without being overlaid, and having no unpleasant smell. A first 

 glance at one of these cards would lead one to suppose that the 

 eggs were artificially attached to the card, but the regularity is 



