ZOOLOGICAL AND BOTANICAL ASSOCIATION. 55 



up, to which he requested the attention of the members present, hoping 

 that they might bo induced to undertake the solution of some of the 

 numerous questions connected with tins much neglected branch of in- 

 quiry ; and concluded by enforcing the importance of development, not 

 merely for the determination of the homology of parts, but also for as- 

 certaining the relative positions of the numerous forms of which the 

 animal world is made up. 



An extensive series of diagrams was exhibited in illustration of the 

 several statements made by the author. 



Robert M'Donnell, M. D., M.R.I. A., Lecturer on Anatomy and 

 Physiology in the Carmichael School of Medicine, Dublin, read the 

 following paper — 



on the electrical nature op the power possessed by the actinia op 



our 8hores. 



Among the many important researches of modern physiologists, few are 

 more interesting than those connected with animal electricity. The 

 sagacity and perseverance of Professor Matteucci. and of M. Nobili, and 

 others among their countrymen, have brought to light several important 

 facts on this subject, more particularly as regards the electrical currents 

 generated by organic matter. It is not, however, to electricity artifi- 

 cially generated by piles, made of either organic or inorganic matter, that 

 it is intended to invite attention in the present communication, but to 

 tho electrical power possessed by some animals, and which is capable of 

 being exercised by them under voluntary influence. It is true the ani- 

 mals hitherto ascertained to be so endowed are not numerous : the Tor- 

 pedo l the Gymnotus, and the Silurus, are the best known, and from them 

 the most unequivocal evidence of electrical power has been obtained. 

 The Trichiurus electricus, and the Tetraodon electricus, besides some other 

 inhabitants of the tropical seas, are said to be able to give shocks, but 

 their electrical power has not yet been proved by direct experiment. 



Certain insects likewise have been supposed to possess some power 

 resembling animal electricity, and we are told that the Sepia hexapodia, 

 and also the Alcyonium bursa, a native of the German Ocean, produce a 

 degree of numbness in the naked hand when brought in contact with 

 them, and for some seconds a sensation resembling an electric shock. It 

 does not appear, however, that any proof has been hitherto offered that 

 electricity is the agent by which these effects are produced. 



