THE YOUNG 



NATUEALIST. 



27 



poisoned stiletto of the bravo, is 

 represented by the exquisite sting of 

 the nettle, no more finished instrument 

 is conceivable for it rivals that perfect 

 weapon the sting of the wasp or bee. 

 The sting of the nettle consists of a 

 sharp-pointed hardened hair surmount- 

 ed by a small knob or ball, con- 

 taining an intensely acrid fluid, of the 

 same nature as formic acid, which 

 is secreted by ants and wasps, and 

 which renders the effect of their stings 

 so acutely painful. So fragile is the 

 little gland of the nettle sting that the 

 slightest touch is sufficient to rupture 

 it, and the fine point of the prickle, 

 bathed in the irritating fluid pierces 

 the skin and produces the well known 

 inflammatory results, which can be 

 counteracted by the emollient juices of 

 the neighbouring dock, every schoolboy 

 knows the old adage " Dock in, nettle 

 out." Another nettle peculiarity is 

 alluded to in the popular rhyme. — 



Gently, gently touch a nettle, 

 And it stings you for your pains, 



Grasp it like a man of mettle, 

 And no hurt your hand sustains. 



This phenomenon is explained by the 

 fact that a quick rough grasp so 

 bruises the fine delicate points of the 

 nettle stings that they cannot pierce 

 the flesh, whilst they respond to gentle 

 handling by insinuating their fragile 

 points into the open pores of the skin, 

 conveying with them the intolerably 

 acrid fluid. 



By gradual transition from prickles 

 and stings we have the all but universal 

 defence of hairs. At first sight it 

 would seem that these apparently feeble 

 organs could exert but little influence 

 upon the plant's welfare, but when the 

 sum of the general attributes of plants 

 are equally balanced, a very little trifle, 

 eveD a hair, will suffice to carry the 

 scale in favour of the one so protected, 

 and when these hirsute appendages are 

 very numerous, as in the mulleins, 

 which seems as if clothed in flannel, 

 such plants must be far less attractive 

 to herbivorous animals. This is very 

 noticeable in the grasses, which may be 

 regarded as the staple food of the 

 browsing animals, those most sought 

 after are smooth and devoid of hairs, 

 whilst those which are freely covered 

 with hairs, such as the brome grasses 

 {Bromus) are passed over and rejected. 

 It is also a curious fact that plants in 

 a wild or natural state are much more 

 efficiently protected than those under 

 cultivation, where man has interposed 

 to disturb the balance of nature and 

 by artificial fences has superseded 

 nature's safeguards. Anyone can 

 verify this by comparing wild carrots, 

 parsnips, oats, &c. with those under 

 cultivation, or by noting the thorny 

 twigs of the sloe, and the spineless 

 branches of the plum, Another 

 powerful protector of plants, although 

 not so patent at first sight, is the acrid, 

 pungent, or poisonous juices secreted 



