INSECTIVOROUS PLANTS 207 



tlie prey. These facts, altliougli mentioned now and 

 then in some succeeding works, were generally forgot- 

 ten, except that of the adhesion of small insects to the 

 leaves of sundews, which must have been observed in 

 every generation. Up to and even within a few years 

 past, if any reference was made to these asserted move- 

 ments (as by such eminent physiologists as Meyen and 

 Treviranus) it was to discredit them. l!Tot because 

 they are difficult to verify, but because, being naturally 

 thought improbable, it was easier to deny or ignore 

 them. So completely had the knowledge of almost a 

 century ago died out in later years that, when the sub- 

 ject was taken up anew in our days by Mr. Darwin, he 

 had, as we remember, to advertise for it, by sending a 

 "note and query" to the magazines, asking where any 

 account of the fly-catching of the leaves of sundew 

 was recorded. 



When Mr. Darwin takes a matter of this sort in 

 hand, he is not likely to leave it where he found it. 

 He not only confirmed all Roth's observations as to 

 the incm'ving of the bristles toward and upon an in- 

 sect entangled on any part of the disk of the leaf, 

 but also found that they responded similarly to a bit 

 of muscle or other animal substance, while to any par- 

 ticles of inorganic matter they were nearly indifferent. 

 To minute fragments of carbonate of ammonia, how- 

 ever, they were more responsive. As these remark- 

 able results, attained (as we are able to attest) half a 

 dozen years ago, remained unpublished (being portions 

 of an investigation not yet completed), it would have 

 been hardly proper to mention them, were it not that 

 independent observers were beginning to bring out 



