PROFITABLE CULTIVATION OF THE OYSTER. 881 



mals, to which the oyster belongs, the propagation of the species is se- 

 cured not by a long period of nursing, but by producing so large a num- 

 ber of young ones that, in spite of all the destructive influences to 

 which they are exposed, a certain number invariably live to grow to 

 maturity. But this remnant of the full-grown ofl'spriug of the mother- 

 oyster is, even in the best and most carefully managed beds, so small 

 that I feel convinced no one would credit my statements if I could not 

 l^rove their correctness by authenticated figures. 



The Schleswig-Holstein oyster-beds were, in the year 1587, seized by 

 King Frederick I of Denmark, as property of the crown. Since the 

 beginning of the eighteenth century they were rented, generally for a 

 long number of years. In order to prevent their being exhausted, the 

 government had these beds officially examined from time to time. la 

 the presence of the government officials, the oyster fishers had generally 

 to throw out their nets in three different places in every bed. A\\ the 

 oysters which they caught were separated into three classes : " Zahlbar 

 gut,'^ marketable goods; '•'-jung gut,''^ joung oysters; and ^'■junger 

 anivacJis,^^ the youngest and scarcely developed oysters. The first class 

 comprised the full-grown oysters. They are at least 9 centimeters long 

 and broad. Most of them are seven to ten years old, some even older, 

 the oldest being, according to my estimate, twenty to thirty years. The 

 second class comprises the half-grown oysters, measuring less than 9 

 centimeters, and being three to six years old. The third class com- 

 prises the smallest oysters, one to two years old. In the official reports 

 it is mentioned how many of the first two classes were taken at every 

 haul. Those of the third class were not counted, but it is merely men- 

 tioned whether the quantity taken was large or small. 



Between the years 1730 and 1852 all the oyster-beds were examined 

 ten times. In comparing the number of grown and half-grown oysters 

 taken at each of these inspections, we find figures which differ very 

 much from each other, and do not seem to indicate any leading rule 

 or principle. But if from these figures we calculate the proportion of 

 half-grown to full-grown oysters at every inspection, we find the aston- 

 ishing result that this proportion scarcely varies at all, and if we take 

 the average of these ten inspections, we find to every ],000 full-grown, 

 oysters not more than 421 half-grown ones. The half-grown oysters 

 make the total of grown young ones produced by the full-grown oysters 

 of a bed. How small does this number, 421, seem if compared with the 

 immense number of young produced by a full-grown oyster ! I said 

 before that in our beds at least 44 per cent; of all full-grown oysters lay 

 eggs. Of 1,000 oysters, 440 would, therefore, lay eggs, and as every 

 full-grown oyster lays at least 1,000,000 eggs, we would, of 1,000 full- 

 grown oysters in one bed, get at least 440,000,000 young oyst( rs ; but 

 as, on an average, only 421 grow to maturity, we lose, for every Holstein 

 oyster which comes on the table, 1,045,000 young oysters. By sacrifi- 

 cing this immense number of young oysters, nature secures a mature 

 age to a few. 

 56 F 



