352 SOCIETY OF PHYSICS AND NATURAL HISTORY, OF GENEVA. 



those of the large cysts by their shorter tails. However, with a great 

 many of them the tail was bifurcated at the end. Prof. Claparede 

 also exhibited the platCKS of a uewwork upon the histology of Anne lides, 

 and has given some details as to the process he employs for the arrange- 

 ment and preservation of his preparations. 



M. Hernjan Fol read before the society a long and important memoir 

 npoii the Appendiculaires, a family belonging to the class of Tuniciers 

 It confirms the near relation that several authors have established be- 

 tween these animals and vertebrates, and proposes to place them at 

 the base of the genealogical tree of the latter. M. Fol has been made a 

 member of onr society on account of this work, which will be printed 

 in Volume XX of onr memoirs. 



M. Godlrey Lunel has given some interesting facts observed at Ge- 

 neva relative to the metamorphoses of the Axolotes. We know that 

 these batracians are transformed sometimes by the loss of their bron- 

 chia, and, from being aquatic, as they generally are, they become pul- 

 monary animals, living in free air. Several Axolotes, placed in running 

 water, did not experience any change; while of two others, left in a 

 wash-basin, badly cared-for and exposed to the cold, one died, and the 

 other was transformed by the loss of its bronchia ; but, after having 

 been replaced in a normal condition, it re-assumed its first form so 

 perfectly as not to be distinguished. This fact, which constitutes a sec- 

 ond transformation in a retrograde direction, is entirely new. 



Dr. J. L. Prevost has given an account of experiments relative 

 to the mode of action of anaesthetics and of chloroform upon the ner- 

 vous center, and he has obtained results contrary to those of M. CI. 

 Bernard. This physiologist states that the chloroform, in acting up- 

 on the brain, affects not only that organ, but acts also, at a distance, 

 upon the spinal marrow, without being in contact with it. M. Prevost 

 has repeated the principal experiments of M. Bernard, which consist 

 in stopping the circulation in frogs, by placing a bandage below the 

 shoulders, then injecting diluted chloroform into one set below the skin 

 of the anterior cut, and into the other below the skin of the posterior 

 cut. In varying the position of the frogs, M. Prevost, after trial, 

 has found that chloroform introduced in the posterior part can, 

 contrary to the opinion of M. Bernard, an£estli,etize the anterior part 

 when the frog is placed with the posterior members in the air, while 

 the chloroform introduced in the anterior part does not aniesthetize the 

 posterior part if we are careful to place the frog with the head down- 

 ward. He thinks that M. Bernard has not been sufficiently careful to 

 guard against the liltration of the chloroform through the tissues. 



M. Prevost, in applying pure chloroform to the denuded brain of 

 a frog, of which the aorta was tied, and placed in the position above 

 indicated, has aniesthetize the head only of the animal, leaving intact the 

 functions of the spinal marrow. Afterward, when he has untied 

 the aorta, these frogs have returned to their normal state, which proves 



