THE GENERATIVE ORGANS OF THE OYSTER. 



279 



or nearly ripe ova ; these they would have emitted in a few days. 

 Others^ again, contained spermatozoa either ripe or nearly ripe — one 

 could see that they would participate in the season^s breeding. On 

 the contrary, the oysters which contained young cells producing ova 

 and sperm mother-cells were in a condition in which it was very 

 difficult to determine whether they would participate in the season^s 

 breeding, and what would be their function. 



According as the male or female elements appeared to predomi- 

 nate they were classed as likely to become males or females. A 

 certain number, though not many oysters remained in which the 

 sexual organs were very feebly developed. It is impossible to say 

 whether these oysters had already bred, or whether they were weak 

 or diseased. 



The results of the examination of 190 oysters from each locality 

 are given in the following table : 



Condition of reproductive organs. 



A. Oysters with white spat . 



B. „ with black spat . 



C. „ with ripe or nearly ripe ova 



D. ,, with ripe or nearly ripe spermatozoa 



E. „ which seemed likely to become females 



F. ,, which seemed likely to become males 



G. „ with ill- or non-developed reproductive organs 



Total number of oysters examined 



Cultivated 

 oysters. 



11 



17 

 21 

 75 

 11 



17 

 38 



190 



Natural 

 oysters. 



19 

 12 



42 



94 



7 



6 



10 



190 



Of 190 cultivated oysters, there were at least 49 functional 

 females, and of the same number of natural oysters, 73, or 12^ per 

 cent, more, were functional females. But the more numerous exam- 

 ples of cultivated oysters classed under E should probably be classed 

 as females, and thus the difference is made less ; and since many of 

 those classed under G had doubtless acted as females, the difference, 

 which looks large at first, loses its importance. The same is the 

 case with the males. The advantage remains with the natural 

 oysters, but the advantage is so small that any conclusions founded 

 on these data would be valueless. 



One circumstance shown in the table is remarkable. The culti- 

 vated oysters are in advance of the natural oysters in their develop- 

 ment at a certain season of the year. Ordinarily the consignments 

 received comprised an equal number of the two kinds, so that they might 

 be considered as having been opened at the same date. If we allow 

 that, of those classed under G, one half had been functional females. 



