No. 6.] HOOKER — CARNIVOROUS HABITS OF PLANTS. 355 



More recently, however, they have been repeatedly verified : 

 in Germany by Nilschke, in 1860; in America by a lady, Mrs. 

 Treat, of New Jersey, in 1871 ; in this country by Mr. Darwin, 

 and also by Mr. A. W. Bennett. 



To Mr. Darwin, who for some years past has had the subject 

 under investigation, we are indebted, not merely for the complete 

 confirmation of the facts attested by the earliest observers, but 

 also for some additions to those facts which are extremely im- 

 portant. The whole investigation still awaits publication at his 

 hands, but some of the points which were established hive been 

 announced by Professor Asa Gray in America, to whom 31 r. 

 Darwin had communicated them. 



Mr. Darwin found that the hairs on the leaf of Drosera le- 

 sponded to a piece of muscle or other animal substance, while to 

 any particle of inorganic matter they were nearly indifferent. 

 To minute fragments of carbonate of ammonia they were more 

 responsive. 



I will now give the results of Mrs. Treat's experiments, in her 

 own words : — 



"Fifteen minutes past ten I placed bits of raw beef on some 

 of the most vigorous leaves of Drosera longifoUa. Ten minutes 

 past twelve two of the leaves had folded around the beef, hiding- 

 it from sight. Half-past eleven on the same day, I placed living 

 flies on the leaves of D. longi/oUa. At twelve o'clock and forty- 

 eight minutes, one of the leaves had folded entirely round its 

 victim, and the other leaves had partially folded, and the flics had 

 ceased to struggle. By half-pnst two, four leaves had each folded 

 around a fly. The leaf folds from the apex to the petiole, after 

 the manner of its vernation. I tried mineral substances, bits of 

 dried chalk, magnesia, and pebbles. In twenty-four hours 

 neither the leaves nor the bristles had made any move in clasping 

 these articles. I wetted a piece of chalk in water, and in less 

 than an hour the bristles were curving about it, but soon unfolded 

 auain, leavinsj: the chalk free on the blade of the leaf." 



Time will not allow me to enter into further details with 

 respect to Diousea and Drosera. The repeated testimony of 

 various observers spreads over a century, and though at no time 

 warmly received, must, I think, satisfy you that in this sm al 

 family of the Dioseraceaj we have plants which in the first plac 

 capture animals for purposes of food, and iq the second, dige 

 and dissolve them by means » a fluid which k Doured out 



