178 L'(j^al Soviefi/ : — 



the woodcuts liere given, aud drawn, in the presence of the writers, 

 at Dr, Pio-ott's house by the accurate artist Mr. Holhck, deaf and 

 dumb and a rapid delineator without the camera. Mr. Beau- 

 mont's surprise and admiration equalled that of Dr. Pigott. This 

 circumstance will excite no surprise when it is stated that for four 

 years the spherules of the Podtira have been generally denied 

 and warmly disputed. In ordinary cases a crushed scale shows 

 nothing ; and as glasses are usually corrected to show the iEusory 

 spines or markings, these spherules are concealed. 



The idea couveved was, that two layers of spherules (first de- 

 tected by Mr. Beaumont within the tubes), like two confined 

 layers of small shot, had, by compression, been forced and largely 

 spread out into broader layers. It was thought also that detached 

 portions resembled long tubes or puckers filled with spherules 

 exactly fitting them. The spherules appeared perfectly spherical, 

 but somewhat unequal in size. 



In the general flattened and extended surface of the compressed 

 and disintegrated scale the spherules appeared dark blue or red, 

 according to the slight change in the focal plane, aud in a still 

 lower plane white. 



In the adjoining uninjured scales long strings of beads were 

 seen, like necklaces of coral, here and there sharply bordered 

 with black lines, apparently denoting tubes of membrane or 

 puckers enclosing them like a tube. Between these strings of 

 spherules peeped forth others of a light orange-colour. 



The slide was an old one and w^ell known. The mass of the 

 crushed scale occupied a much broader space than any of the 

 scales. 



November 20, 1873. — Su- George Biddull Airy, K.C.B., President, 

 in the Chair. 



" Note on the Electrical Phenomena which accompany irritation 

 of the leaf of Dioncea muscipida" By J. BuRDOJf Sanderson, 

 M.D., P.E.S., Professor of Practical Physiology in University 

 College. 



1. When the opposite ends of a living leaf oi Dioncea are placed 

 on non-polarizable electrodes in metallic connexion ^ith each 

 other, and a Thomsons reflecting galvanometer of high re- 

 sistance is introduced into the circuit thus formed, a deflection is 

 observed which indicates the existence of a current from the 

 proximal to the distal end of the leaf. This current I call the 

 normal leaf-current. If, instead of the leaf, the leaf-stalk is placed 

 on the electrodes (the leaf remaining united to it) in such a way 

 that the extreme end of the stalk rests on one electrode and a part 

 of the stalk at a certain distance from the leaf on the other, a 

 current is indicated which is opposed to that in the leaf. This I 

 call tbe stalk-current. To demonstrate these two currents, it is not 

 necessarv to expose any cut surface to the electrodes. 



