40 • OPHKE^.- _ Chap. I. 



between the two membranes. So copious is this fluid, 

 that, after cutting off the extremities of the nectaries 

 of 0. jpyramidalis, and gently squeezing them on glass 

 under the microscope, such large drops of fluid exuded 

 from the cut ends, that I concluded that at last I had 

 found nectaries which contained nectar; but when I care- 

 fully made, without any pressure, a slit along the upper 

 surface of other nectaries from the same plants, and 

 looked into them, their inner surfaces were quite dry. 

 I then examined the nectaries of Gymnadenia conopsea 

 (a plant ranked by some botanists as a true Orchis) 

 and of Habenaria bifolia, which are always full of nectai 

 up to one-third or two-thirds of their length. The 

 inner membrane presented the same structure and was 

 covered with papillae as in the foregoing species ; but 

 there was a pla,in difference in the inner and outer 

 membranes being closely united, instead of being in 

 some degree separated from each other and charged 

 with fluid. I was therefore led to conclude that insects 

 • penetrate the lax inner membrane of the nectaries of 

 the above-named Orchids, and suck the copious fluid 

 between the two membranes. This was a bold hypo- 

 thesis; for at the time no case was known, of insects 

 penetrating with their ■ delicate proboscides even the 

 laxest membi-ane. But I have now heard from Mr. 

 Trimen, that at the Cape of Good Hope nioths and 

 butterflies do much injury to peaches and plums by 

 puncturing their unbroken skins. In Queensland, 

 Australia, a moth, the Ophideres fullonica, bores 

 through the thick rind of the orange with its wonder- 

 ful proboscis, provided with formidable teeth.* There 

 is therefore not the least diiBculty in believing that 

 Lepidoptera with their delicate proboscides, and bees 



* My son Francis has described ' Q. Journal of Microscopical 

 and figured this organ in the Science,' vol. xv. 1875, p. 385. 



