AS COMPARED WITH THAT OF OTHER VENOMOUS SNAKES. 131 



containing two specimens of Paramceciiuii in active motion, was' 

 examined. They were rotating with great rapidity. A little 

 cobra-poison diluted with water was added. Three minutes 

 after the addition one was discovered with both the cilia and 

 cell-body perfectly still. The cilia of the other were still, but 

 the cell-body was contracted. In about half a minute more it 

 expanded to its normal size and then remained perfectly still. 



Experiment XXXII. 



A piece taken from the mantle of a freshwater mussel was 

 placed on the slide and examined at the end of about half an 

 hour. Active ciliary motion could be observed in the fringe of 

 the mantle itself and in several specimens of Paramcecium. A 

 little dilute poison was added. At first the ciliary motion 

 seemed increased, but in about 2 minutes it became slower, and 

 in 6 had become very languid, and in 10 minutes stopped 

 altogether in the specimens of Paramcecium, but still continued 

 in some of the cilia of the mantle. 



Experiment XXXIII. 

 A little dilute cobra-poison was added to a piece of the mantle 

 of a freshwater mussel. The cilia began immediately to move 

 much more rapidly. This was watched for some time. Ciliary 

 motion not affected, or at all events not arrested, after more 

 than half an hour. 



Experiment XXXIV. 



December 10th, 1874. — A piece of the gills of a freshwater 

 mussel placed under the microscope and a little cobra-poison 

 added at 10.40 p.m. The cilia Vi^ere extremely active. 



At 10.55 still active. 



11.5. Several ciliated amoeboid masses are now quiet instead 

 of rolling over and over as they did, but the cilia on their 

 surface are still moving. 



11.15. The cilia on these Infusoria have now nearly all 

 stopped. A few are moving slowly, whilst those on the gills 

 are but little affected. 



(95) K 2 



