248 



♦ KNOWLEDGE ♦ 



[September 1, 1888 



usually quite straight, though always sharply twisted up 

 upon its own axis, seven or eight revolutions being usually 

 observable. At the top of the shaft there is a bend, usually 

 somewhat larger than a right angle, which is termed the 

 "lower knee," and in about half an inch another sharper 

 bend, which has been called the " upper knee," after which 

 the awn is still further produced into a stiff tapering bristle, 

 somewhat less than three inches in length, entirely un- 

 twisted, and set with many exceedingly minute but sharp 

 teeth, all pointing backwards. The whole apparatus, for 

 such it may be called, is thus about six or seven inches 

 in length. A glance at the accompanying illustration, 

 however, will give a clearer idea of the seed than the most 

 elaborate description. 



The foregoing is a description of the instrument when in a 

 perfectly dry state. On its becoming wet, the " hygrometric 



Awn op Stipa Spartea Cin its dry or twisted state). 



action " of the awn (as it is called) comes into play, and the 

 appearance of the whole contrivance quickly becomes 

 changed. The shaft then begins to untwist, the knees com- 

 mence to straighten, and in a short time the whole awn 

 becomes perfectly straight from end to end, so to remain 

 until it is again dried, when the former twisted and bent 

 condition is resumed. This curious power of untwisting 

 and straightening itself when moistened, and of again twist- 

 ing up when dried, seems to continue for an almost indefinite 

 time — probably until the awn commences to undergo 

 natural decay. It is a power which is also possessed, 

 though in a less fully-developed degree, by various other 

 seeds. In most, if not all, of the members of the genus 

 Stipa, in several other grasses, in some of the Erodiums, and 

 even in the common wild oat, this curious hygrometric 

 peculiarity of the seed is observable. 



Let us now examine how this power aids the seed in its 

 nefarious designs. It is in this way : Suppose a ripe awn, 

 in its dry or twisted state, to have become entangled in the 

 wool of a sheep, or to have fallen among the grass. It there 

 remains inactive, until moistened by a shower of rain or a 

 heavy dew. Then, as we know, the shaft commences to 

 untwist, rotating the point of the seed ; for, as the bristle 

 or arm of the awn forms at first a right angle with the shaft, 

 it is certain to catch in the grass or wool, and thus prevent 

 the head of the shaft from revolving as it untwists. But all 

 this time, as we also know, the " knees " are straightening, | 



raising the arm and causing it to press upwards. In rising 

 it will probably pi-ess against a blade of grass or catch in 

 the wool, its many fine teeth affording it a more or less firm 

 hold upon either. Under these circumstances, the continued 

 ellbrts of the arm to rise will have the effect of pressing for- 

 ward the revolving point of the seed, causing it to penetrate 

 slowly and by degrees into the flesh of the animal, the 

 ground, or any other sufficiently soft substance which may 

 be opposed to it. Thus our automatic boring-ajiparatus 

 wiU be in full operation. Having penetrated to a slight 

 depth, the barb-like hairs I'ound the point prevent it being 

 withdrawn when the awn re-twists on again becoming dry ; 

 so there it remains, ready to penetrate further and further 

 as often as succeeding drought and moisture cause the awn 

 to twist and untwist again. 



There is, as has been ah'eady said, no question that the 

 seeds are in this way able to penetrate the skins of animala 

 and actually enter the bod}-. On the plains of the West its 

 possession of this power is well known, and I have myself 

 often seen and heard of instances of its effect. I have 

 never, it is true, actually seen a sheep that had been 

 thus killed, because sheep are not allowed to die of it, 

 but are killed for the butcher. There is, however, not the 

 least question that the seeds have the power of causing 

 death, either directly or indirectly. A recent American 

 writer, speaking of this subject, says that, after the seeds 

 have penetrated the skin, " the awns bi'eak off, and the 

 needles penetrate the vital part of the sheep, causing pain- 

 ful death. . . . The points, too, not only enter the body of 

 the sheep in this way, but also stick in the nostrils, nose 

 and hps, where, however, they do less harm than when 

 eaten and swallowed into the stomach, in which event 

 death must follow." I have been repeatedly assured when 

 "out West," by butchers and others, that the "spears" 

 are very commonly found beneath the skins of sheep after 

 death — especially about the shoulders — indeed, I have 

 myself seen them in this position, while I have been several 

 times told by settlers of sheep they had been compelled to 

 kill, " to save their lives," as Irishmen are supposed to say. 

 I have, moreover, demon.strated that the seeds do possess 

 this power bj- experiment in England. Some seeds, which 

 I placed among the wool of two sheep, quickly penetrated 

 to a depth of half an inch, after which I removed them, 

 thinking that the animals were probably less interested than 

 myself in the lesult of my experiment. Indeed, the keep- 

 ing of sheep on the Western prairies would be rendered 

 almost impossible, on account of the prevalence of this 

 deadly grass, were it not for the fact that its evil effects can 

 be avoided by a few simple precautions, such as a careful 

 examination of the sheep during the time the seed is ripe, 

 or " folding " them during the same period. 



But sheep are not the only animals that sufft'r. W^oolly- 

 haired dogs are almost equally troubled, if proper care be 

 not taken. I have heard of such dogs having, like the 

 sheep, to be killed " to save their lives," when the whole of 

 the breast and stomach has been found to be a mass of 

 ulceration. I have also heard of a colley, which came so 

 thoroughly to understand the nature of the " spears," that 

 he would never enter the long grass while they were ripe ; 

 while one settler told me that he had found it necessary to 

 shave his dog all over when the " spears " were ripe, to pre- 

 vent their catching in his long matted hair. 



Now, could any epithet be too strong to describe correctly 

 a seed which conducts itself in such an atrocious manner? 

 I think not. It mu.st, however, be confessed that it is a 

 little difficult to see exactly how the plant is banefited by 

 its seeds being introduced into the bodies of animala. 

 Their dispersal would, it is true, be usually assured, but the 

 great object of that dispersal — namely, germination — would 



