106 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



The table shows sufficiently that in the specimens which were exam- 

 ined the cultivated oysters exceeded the uncultivated. This observa- 

 tion is confirmed by the assertion of oyster cultivators, namely, that 

 uncultivated oysters deposit their spawn later than the cultivated. In 

 oyster regions where it is certain that the large mass of spawn to be 

 gathered comes from uncultivated oysters, the tiles are laid some time 

 after those placed in regions destined for cultivated oysters. 



As regards the age which is necessary for reproduction, my investi- 

 gations did not lead to any definite result, because nearly all the oysters 

 which I received' were of the same age. The majority were three or 

 four years old, and some two or five years old. Even if there had been a 

 greater difference of age, the number of oysters would have been much 

 too small to yield absolutely certain results as regards this question. 



In conclusion, I must state my opinion as to the manner in which 

 these investigations should be carried on in order to reach a sure result. 

 The investigations should commence in March and be continued till 

 October. Every month about the same date a sufficiently large num- 

 ber (at least 100) of oysters, two, three, and four years old, should be 

 opened — an equal number of each kind, cultivated and uncultivated. 

 An incision which will solve all doubts as regards the sexual organs 

 should be made in each oyster. Only such a process would -furnish 

 figures which could allow a comparison. 



Supposing for a moment that the result would be that the number 

 of females did not differ much in each kind, it would still be incorrect 

 to judge therefrom that the great mass of spawn floating about had 

 not been produced by uncultivated oysters. The spawn of these latter 

 may be stronger than that of the cultivated oyster ; and I think I may 

 admit that the quantity of spawn produced by an uncultivated oyster 

 is larger than that produced by a cultivated one. 



We see, therefore, that many so called facts are only more or less 

 weak probabilities, and that very few of these facts have been proved. 

 The great value of earnest and accurate investigations would, especially 

 in the beginning, not consist in proving many facts, but rather in point- 

 ing out the direction in which these investigations should be made. 

 We have experienced sufficiently the truth of this in studying the mode 

 of life and the physiology of that mysterious little animal, the oyster, 

 and any one who has taken the trouble to gather some knowledge ^)f 

 the complicated processes of reproduction will not be surprised at this 

 statement. 



