END OF THE EXPERIMENT. 233 



Several SerpuhB. 



Acaridce. 



Entomostraca. 



Infusoria. 



Grantia nivea. And other smaller zoophytes and 

 sponges which I could not identify. 



Soon after this examination I went on a journey, 

 and did not return till the 7th of July. The weather 

 had set in very hot : whether this, comhined with the 

 closeness of the room, had had any effect I do not 

 know; hut on my return I found the water heginning 

 to he offensive, a sort of scum forming on the surface, 

 and the animals evidently dying. Some were already 

 dead, hut most of the others recovered on heing 

 removed to fresh sea-water. This result, though it 

 puts an end to my experiment at this time, I do not 

 regard as conclusive against the hypothesis ; for of 

 course animals are liahle to death under any circum- 

 stances, and the corrupting body of one of these in so 

 limited a volume of water would soon prove fatal to 

 others, even though there might be no lack of oxygen 

 for respiration. It is possible that one of the large 

 Actinia} may have casually died during my absence, 

 the timely removal of which might have averted the 

 consequences to the others; but this is only conjec- 

 ture. Perhaps there was too large an amount of 

 animal life in proportion to the vegetable ; but the 

 maintenance of all these in health and activity for 

 nearly nine weeks seems hardly to agree with such a 

 supposition. 



Should these experiments be perfected, what would 

 hinder our keeping collections of marine animals for 



