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time, their importance would seem to have been considered paramount, lie compared the 
Fly's foot with that of Dyticus ; but the superficial observations he made of the latter 
go to prove that he cannot have used a magnifier of any kind in examining the great 
Water-beetle; or he could not have failed to observe parts (viz. the great suckers : to 
eye practised in minute observation, the whole set of small suckers as well) clearly enough 
visible to the naked eye. His words shall speak for themselves. After simply saying, 
" I might here name divers flies and other insects, who, besides their sharp-hookcd-nails, 
have also skinny palms to their feet to enable them to stick on glass and other smooth 
bodies, by means of the pressure of the atmosphere," he adduces the following proof of 
the correctness of his explanation respecting the action of Flies' feet :— " But because tin 
example will illustrate another work of Nature, as well as this, I shall chusc a singular 
piece of mechanism in one of the largest sorts of Ilydrocanthari. Of these lar 
o 
-< 
there are two sorts, one largest all black, with antenna handsomely emlx -sed at the ends ?? 
(Hydrophilus). " The other somewhat lesser, hardly so black, with capillary antenna ; the 
forehead, edges of the vagina " (elytra), " and two rings on the thorax, of a tawny colour " 
(Dyticus marginalia). The female hath vagina prettily furrowed; the male, smooth. 
But that which is most to our purpose in this male is a flap, or hollowish cap near the 
middle joint of the forelegs, which, when clapped on the shoulders of the female in coite, 
sticks firmly thereon. And then follows the comparison which, for want of duly weigk- 
mg the value of the evidence, has misled, more or less, every succeeding author on this 
subject : — " after the manner as I have seen boys carry heavy stones, with only a wet piece 
of leather clapped on the top of the stone." 
Berham has not a word further on this head ! His observations and remarks evidently 
* 
possess no intrinsic value ; but it was necessary to ascertain distinctly what amount of 
credit was their due, before proceeding further in our inquiry. 
Gilbert "White (1788) * was no microscopist, and in writing on this subject he did but 
repeat the prevalent opinion of his day. He was, however, a shrewd, painstaking observer 
of facts in natural history, who noted the habits of flies as carefully as of the other 
nimals that came under his eye. And because 
has been put upon his 
words which was never intended by their author, and for another reason that will appear, 
it is necessary just to see what he really did say on the present subject. 
Joining, then, in the general belief, he states that " in the decline of the year this re- 
sistance" (the pressure of the atmosphere) "becomes too mighty for their diminished 
strength ; and we see flies labouring along, and lugging their feet in windows, as if they 
D» «■•"•«■ "*30 
stuck fast to the glass, and it is with the utmost difficulty they can draw one foot after 
another, and disengage their hollow caps from the slippery surface." 
This paragraph, when connected with one which precedes it, points to a very curious fact 
in the Natural History of Flies. "As they grow more torpid " (through the advance of 
cold weather) " one cannot help observing that they move with difficulty, and are scarce 
able to lift their legs, which seem as if glued to the glass ; and by degrees many do actually 
stick on till they die in the place." 
It becomes evident from the above that the temporary and voluntary attachment of 
* Natural Historv of Selborne, edition with 
3h2 
