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 incurving of the bristles toward and upon an insect 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 particles of inorganic matter they were nearly indifferent.  To minute fragments of carbonate of ammonia, however, they were more responsive.  As these remarkable results, attained (as we are able to attest) half a dozen years ago, remained unpublished (being portions of an investigation not yet completed), it would have been hardly proper to mention them, were it not that independent observers were beginning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 the same or similar facts.  Mrs. Treat, of New Jersey, noticed the habitual infolding of the leaf in the longer-leaved species of sundew (American Journal of Science for November, 1871), as was then thought for the first time—­Roth’s and Withering’s observations not having been looked up.  In recording this, the next year, in a very little book, entitled “How Plants Behave,” the opportunity was taken to mention, in the briefest way, the capital discovery of Mr. Darwin that the leaves of Drosera act differently when different objects are placed upon them, the bristles closing upon a particle of raw meat as upon a living insect, while to a particle of chalk or wood they are nearly inactive.  The same facts were independently brought out by Mr. A. W. Bennett at the last year’s meeting of the British Association for the Advancement of Science, and have been mentioned in the journals.

If to these statements, which we may certify, were added some far more extraordinary ones, communicated to the French Academy of Science in May last by M. Zeigler, a stranger story of discrimination on the part of sundew-bristles would be told.  But it is safer to wait for the report of the committee to which these marvels were referred, and conclude this sufficiently “strange eventful history” with some details of experiments made last summer by Mrs. Treat, of New Jersey, and published in the December number of the American Naturalist.  It is well to note that Mrs. Treat selects for publication the observations of one particular day in July, when the sundew-leaves were unusually active; for their moods vary with the weather, and also in other unaccountable ways, although in general the sultrier days are the most appetizing: 

“At fifteen minutes past ten of the same day I placed bits of raw beef on some of the most vigorous leaves of Drosera longifolia.  Ten minutes past twelve, two of the leaves had folded around the beef, hiding it from sight.  Half-past eleven of the same day, I placed living flies on the leaves of D. longifolia.  At 12 and 48 minutes one of the leaves had folded entirely around its victim, the other leaves had partially folded, and the flies had ceased to