THE OYSTER. 61 



low, in a few mouth fuls, a number equal to a year's 

 catch. They are also exposed to the weather, and a 

 sudden cold wind or fall in temperature, such as 

 occurred several times during my experiments, killed 

 every embryo. The number which are destroyed by 

 cold rains and winds must be very great indeed. As 

 soon as they are safely past this stage, and scatter and 

 swim at various depths, their risks from accidents and 

 enemies are greatly diminished. Up to this point, 

 which is reached in from twenty-four hours to six- 

 days, there is no difficulty in rearing them in an aqua- 

 rium, provided uniform warm temperature be pre- 

 served. 



Although I failed to keep the young oysters alive 

 until they were large enough to handle and plant, my 

 experiments showed the possibility of rearing them 

 in unlimited numbers, so soon as some practical method 

 of preserving them alive during their infancy should 

 be discovered. 



The next great step in this direction is due to Lieut. 

 Winslow. While I was carrying on my experiments 

 at Crisfield, in 1879, this officer was engaged in ex- 

 amining the oyster-beds of Tangier Sound, and he 

 made frequent visits to the laboratory and learned my 

 methods. The next year, while stationed at Cadiz, 

 Spain, on naval duty, he repeated the experiments 

 with Portuguese oysters, and showed that these, like 

 the American oysters, have the sexes separate, and 

 that the eggs are fertilized in the water; that the 

 young are independent of parental protection, and that 



