laden tables, discovers what appears to be certain 

 evidence that the water it contains is rapidly, 

 almost suddenly, becoming foul. For, only a few 

 hours previous, the aquaria were transparent, 

 and the mother moon-jellies were swimming cease- 

 lessly hither and yon in the crystal clearness with 

 undiminished vigor. But now, in nearly every case 

 the moon-jellies are inactive, some lying on the 

 bottoms pumping lethargically, others apparently 

 dying or already dead. 



Fast following comes another discovery. Gradu- 

 ally the cloudiness of the water becomes concen- 

 trated; a filmy haze settles toward that side of the 

 tanks facing the window light. 



Now, something of this sort, this blanket-like 

 haze, I have seen before. I recall an instance of 

 some fiddler-crabs whose larvae broke from the 

 "sponge," or egg masses carried around by the 

 mothers, and swarmed in myriads toward the light. 

 Can it be that this is an exodus of a similar nature 4 ? 

 ... I examine the jellyfishes. Of course! It imme- 

 diately becomes obvious: the brood-pouches are 

 almost empty, and the creatures' oral appendages 

 are clear as glass. The hazy cloud-like film is com- 



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