DUTROCHET\S KXI'KKIM KNTS. 213 



manner to her eyrie in order to tear it up and part it amongst her 

 eaglets. The vulture, on the contrary, always carries food to the young 

 in her craw, whence she disgorges it when wanted. This, at least, is 

 frequently observed in the species called by the colonists at the Cape 

 stront vogel (dung bird) or aas vogel (carrion bird). It is probable 

 that it holds good in all the vultures, for their talons are not adapted 

 to clutch or to grasp strongly. 



EXPERIMENTS ON THE RESUSCITATION AFTER DEATH OF 

 THE WHEEL ANIMALCULES. 



BY M. DUTROCHET, MEMBER OF THE INSTITUTE, PARIS*. 



THE marvellous property of returning to life after a prolonged desic- 

 cation, has caused the wheel animalcule of Leeuwenhoeck, (Ezechie- 

 lina Leeurvenhoeckii, BORY,) to be much celebrated. I was accordingly 

 anxious to ascertain whether my newly-discovered species were endowed 

 with the same faculty. My first experiments in this respect were made 

 upon the quadricircular wheel animalcule (Rotifera quadricircularis^ 

 DUTROCHET). Knowing that Leeuwenhoeck 's animalcule only resus- 

 citated when preserved from contact with the air by a certain portion 

 of sand while it was drying, I was desirous of trying whether it would 

 resuscitate when dried simply under its own envelope. I accordingly 

 placed on a bit of glass a twig of the water-buttercup, (Ranunculus 

 aquations,) with a number of the wheel animalcules, which I left to 

 dry. In about twenty-four hours I moistened these wheel animal- 

 cules with water, and observed attentively what took place. I had at 

 first a glimmering of hope that I should see them resuscitate, upon per- 

 ceiving a round body issue from each of the envelopes ; but I soon ascer- 

 tained that these bodies, which appeared of a violet colour, were only 

 bubbles of air, which the water had impelled from the interior of the 

 envelopes, and which remained adhering to them. The violet colour 

 arose from the decomposition of the rays of light on the surface of 

 the spherical bubble, an observation which may prevent those who 

 repeat my experiments from being deceived by this optical illusion. 

 I continued then to observe my animalcules ; but although I preserved 

 them for many days in water, I never saw them restored to life. 



* Translated from the French by the Editor. 

 R2 



