INSECTIVOROUS PLANTS. 305 



three feet or more, are never found to contain so many insects 

 as those of the species ahove mentioned. 



" The cause which attracts flies is evidently a sweet, viscid 

 substance resemhling honey, secreted hy or exuding from the 

 internal surface of the tube. . . . From the margin, where it 

 commences, it does not extend lower than one-fourth of an inch. 



" The falling of the insect as soon as it enters the tube is 

 wholly attributable to the downward or inverted position of the 

 hairs of the internal surface of the leaf. At the bottom of a tube 

 split open, the hairs are plainly discernible pointing downward ; 

 as the eye ranges upward, they gradually become shorter and at- 

 tenuated, till at or just below the surface covered by the bait 

 they are no longer perceptible to the naked eye nor to the most 

 delicate touch. It is here that the fly cannot take a hold suffi- 

 ciently strong to support itself, but falls. The inability of in- 

 sects to crawl up against the points of the hairs I have often 

 tested in the most satisfactory manner." 



From the last paragraph it may be inferred that Dr. 

 Macbride did not suspect any inebriating property in 

 the nectar, and in a closing note there is a conjecture 

 of an impalpable loose powder in S.flava, at the place 

 where the fly stands so unsteadily, and from which it 

 is supposed to slide. We incline to take Mr. Grady's 

 view of the case. 



The complete oblivion into which this paper and 

 the whole subject had fallen is the more remarkable 

 when it is seen that both are briefly but explicitly 

 referred to in Elliott's book, with which botanists 

 are familiar. 



It is not so wonderful that the far earlier allusion 

 to these facts by the younger Bartram should have 

 been overlooked or disregarded. With the genuine 

 love of Nature and fondness for exploration, William 

 Bartram did not inherit the simplicity of his father, 



