108 Our Food Mollusks 



was safe once more. The set of 1905 was small and 

 much scattered, as was that also of the year following. 

 The oysters of the natural beds produced very few young. 

 In a few localities the set was good, while neighboring 

 beds were barren. 



Such a sequence of events excites the interest of a 

 biologist as well as that of an oyster culturist. Though 

 oystermen have observed no marked changes in the 

 natural surroundings of the oysters that at one time pre- 

 vent and at another stimulate reproduction, such changes 

 undoubtedly occur. It is possible that a close observer 

 who should, for a long period, keep a daily record of 

 salinity and temperature, and all other conditions known 

 to effect reproduction, would be able to offer a simple and 

 satisfactory explanation of irregularities in the appear- 

 ance of young oysters; or he might be able to discover 

 some other factor, now unknown, that causes the phenom- 

 enon. Whether, after having found the explanation, he 

 would be able to suggest a remedy for the present state 

 of affairs, is another matter; but at least it is certain that 

 the remedy will not be discovered until the cause of the 

 trouble is known. 



