INFUSORIA 453 



ditions in which we are accustomed to see it in higher 

 animals. 



The contraction of the muscle is very sudden, ener- 

 getic, and complete. With a rapidity which the eye can- 

 not follow, the vase is brought down almost to the very 

 base of the stalk. Then it slowly rises again, and now we 

 see, what we could not discern in the act of contraction 

 itself, that in that act the stalk was thrown into an ele- 

 gant spiral of many turns, which at the utmost point of 

 contraction were packed close on each other, but which 

 in the extending act gradually separate, and at length 

 straighten their curves. 



In any stage of the extension, the sudden contact of 

 the vase with any floating or fixed object apparently causes 

 alarm, and induces the vigorous contraction; but vibra- 

 tions, even when so violent as those produced by tapping 

 the stage of the microscope with the finger-nail, have no 

 effect unless the stalk be tense, its own power of vibra- 

 tion being then only developed, just as a cord becomes 

 musical in the ratio of its tension. 



It is not until we view these creatures with a good mi- 

 croscope that we acquire an adequate idea of their beauty: 

 for myself, at least, it was so. I had seen engravings of 

 many of the invisible animalcules, and had read technical 

 descriptions ; but of their brilliant transparency, their sud- 

 den and sprightly motions, their general elegance and deli- 

 cacy, and the apparent intelligence with which they are 

 endowed, neither books nor engravings had given me any 

 conception. 



Some of the individuals under our present examination 

 are exhibiting phenomena of no less interest than their 

 form and motions. Some of the stalks are terminated by 



