18ti EOOT-CLIMBEES. Chap. V. 



are made to press lightly on slips of glass, they emit 

 after about a week's interval, as I observed several 

 times, minute drops of clear fluid, not in the least 

 milky like that exuded from a wound. This fluid 

 is slightly viscid, but cannot be drawn out into 

 threads. It has the remarkable property of not soon 

 drying ; a drop, about the size of half a pin's head, was 

 slightly spread out on glass, and I scattered on it some 

 minute grains of sand. The glass was left exposed 

 in a drawer during hot and dry weather, and if the 

 fluid had been water, it would certainly have dried 

 in a few minutes; but it remained fluid, closely 

 surrounding each grain of sand, during 128 days : how 

 much longer it would have remained I cannot say. 

 Some other rootlets were left in contact with the glass 

 for about ten days or a fortnight, and the drops of 

 secreted fluid were now rather larger, and so viscid 

 that they could be drawn out into threads. Some 

 other rootlets were left in contact during twenty-three 

 days, and these were firmly cemented to the glass. 

 Hence we may conclude that the rootlets first secrete 

 a slightly viscid fluid, subsequently absorb the watery- 

 parts, (for we have seen that the fluid will not dry 

 by itself,) and ultimately leave a cement. When the 

 rootlets were torn from the glass, atoms of yellowish 

 matter were left on it, which were partly dissolved 

 by a drop of bisulphide of carbon ; and this extremely 

 volatile fluid was rendered very much less volatile by 

 what it had dissolved. 

 4-3 the bisulphide of carl^op has a strong power 



