48 THE POPULAR SCIEXCE MONTHLY. 



jaded. It not only could be surfeited, but it suffered from indigestion; 

 and a meal of cheese disagreed with the leaves so seriously as finally 

 to kill them. 



Finally, Dr. Burdon-Sanderson has made an imjiortant contribution 

 to this investigation, by demonstrating the correspondence between 

 the electrical phenomena which accompany muscular action and those 

 which are associated with the closing of the Dionaea-leaf He has 

 shown that, not alone in the electrical but in structural changes w^hich 

 ensue, the resemblance is complete between the contraction of muscle 

 and that of the leaf; and, the further the inquiry is pursued, the more 

 striking does the resemblance appear. 



Drosera. Unlike the preceding genus, which is confined to a sin- 

 gle district, the sundews are widely distributed. The fact that they 

 are closely related to the Dioncea was little known when the curious 

 habits, which are now attracting so much attention, were first dis- 

 covered. 



Mr. Gardom, a Derbyshire botanist, gives an account of what his 

 friend Mr. Whateley, an eminent London surgeon, made out in 1780: 

 " On inspecting some of the contracted leaves we observed a small 

 insect very closely imprisoned therein, which occasioned some aston- 

 ishment as to how it happened to get into so confined a situation. 

 Afterward, on Mr. Whateley 's centrically pressing with a pin other 

 leaves yet in their natiiral and unexpanded form, we observed a 

 remarkably sudden and elastic spring of the leaves, so as to become 

 inverted upward, and, as it were, encircling the pin, which evidently 

 showed the method by which the fly came into its embarrassing 

 situation." 



This account, which is erroneous in representing the movement of 

 the hairs as much more rapid than it really is, must have been written 

 from memory. 



In July of the preceding year (though the account was not pub- 

 lished till two years afterward). Roth, in Germany, had remarked, in 

 Drosera rotuncUfolia and longifolia, that " many leaves were folded 

 together from the point toward the base, and that all the hairs were 

 bent like a bow." Upon opening these leaves, he says : " I foimd in 

 each a dead insect ; hence I imagined that this plant, which has some 

 resemblance to the Dlonma muscipula,va\ ght also have a similar mov- 

 ing power. . . . With a pair of pliers I placed an ant upon the middle 

 of the leaf of D. rotundifoUa. The ant endeavored to escape, but 

 was held fast by the clammy juice at the points of tl)e hairs, which 

 was drawn out by its feet into fine threads. In some minutes, the 

 short hairs on the disk of the leaf began to bend, and in some hours 

 the end of the leaf was so bent inward as to touch the base. The 

 ant died in fifteen minutes, which was before all the hairs had bent 

 themselves." 



These facts, established nearly a century ago, by the testimony 



