500 ^ological Proceeifiugs ()f Societies. 



these and other facts tb conclucle that such unions oi swarms are genera llyV'-' 

 if not 2tlways,'^he result of pj^vious concert and' arrangement. 



He next proceeds to mention some circumstances which induce him to 

 beheve that sex is not given to the eggs of birds^ or to thespawn oi fishes 

 or insects, at any^very early 'period of their growthf^Female ducks, 

 kept apart from any male bird till the period of laying eggs approached, 

 when a nausk drake wa&^put int9 company with them produced a nume- 

 rous offspring, six ouit of seven of which proved to be males. 



The mule-feshes found in many rivers where the common trout abounds, 

 and where a solitary salmon is present, are uniformly of the male sex : 

 ^jihence the spawri must .have been without sfex at the time it was deposited 

 by the female. 



Mr. Knight states that he has also met with analogous circumstances in 

 the vegetable world, respecting 1^^ sexes of the blossoms of monoicous 

 plants. When the heat is exc^sive, compared with the quantity of light 

 which the plant receives, only male flowers appear : but if the light be in 

 excess, female flowers ailone are produced. 



JVov. 20. — ^ilt.paper was read, entitled j^n Account of some Experi- 

 ments on the Torpedo : by Sir Humphry Davy, Bart., F.R.S., &c. 



The authour, after noticing the peculiarities jdiscovered by Walsh in 

 the elec^jjSity of the Torpedo, and th^ opinion^of Cavendish that it re- 

 sembles the action of the electrical battery weakly charged, adverts to 

 the conjecture of Volta, who considered it as similar to that of the gal- 

 *yanic pile. Being on the coast of the Mediterranean in 1814 and 1815, 

 the authour, desirous of as'certaming the justness of V^a's comparison, 

 passed the shocks given by living Torpedos through the intcTTupted cir- 

 cuit made by silver wire through water, but could not perceive the light- 

 est decomposition of that fluid ; the, same shocks, made to pass through 

 a fine silver wire, less than one-thousandtli of an inch in diame|^, did 

 not produce ignition. Volta, to whom the authour communicated th^ 

 results of these experiments, considers the condition of the organs of 

 the Torpedo to be best represented by a pile of which the fluid substance 

 was a very imperfect conductor, such as honey, and which, though it 

 communicated weak shocks, yet did not decompose water. 



The authour also ascertained that the electrical shocks of the Torpedo, 

 even when powerful, produced no sensible effect on an extremely deli- 



1 



