May 29, 1890] 



NATURE 



115 



first two cats about the end of March ; and the question arises as 

 to how the disease originated in these two animals. No cats had 

 been ill in their shed, and the two affected ones were healthy 

 when received at the institution some weeks before. But during 

 the latter half of March there were in the stables of the institution 

 two milch cows ill with diphtheria induced by inoculation with 

 the human diphtheria bacillus — in fact, the two cows already 

 referred to. The diphtheria bacillus was found in the milk drawn 

 from one of these animals on the fifth day after inoculation, and 

 orders were given to the attendant that the milk of both cows 

 was to be thrown away. This order was not obeyed, for part of 

 the milk was given to the two cats above mentioned, and they 

 sickened as described within a day or two afterwards. It ought 

 to be mentioned that the man in attendance on the cows had also 

 charge of the cats, but, in view of the fact thai he was himself 

 free from the disease, the possibility of his having conveyed it 

 from the cows to the cats may be disregarded. 



SOME NOTES FROM SOUTH AMERICA. 



TN the course of a visit to the plains of South America, not 

 •*• far from Ro?ario de .Santa Fe, in the Argentine Hepublic, 

 lasting from September 1888 until March 1889, I was able to 

 make some miscellaneous notes of more or less interest. From 

 these I select the following : — 



(1) The Rhea, or South American Ostrich.— The cock bird 

 makes the nest, hatches the egg?, and takes care of the young 

 birds. We had some (so-called) "tame" ostriches about the 

 esiaiicia. One day I came across the old cock in a nest that it 

 had made in the dry weeds and grass. Its wings and feathers 

 were loosely arranged, and looked not unlike a heap of dried 

 grass ; at any rate the bird did not attract my attention until I 

 was close on him. The long neck was stretched out close along 

 the ground ; the crest-feathers were flattened ; and an appalling 

 hiss greeted my approach. It was a pardonable mistake if for a 

 moment I thought I had come across a huge snake, and sprang 

 back hastily under this impression. This might be cited as an 

 instance of (unconscious) "protective mimicry." 



When a troop of these birds is alarmed while yet at a dis- 

 tance from the enemy, they run with their wings either clos.-? to 

 the side in the normal position, or raised above the back into a 

 narrow wedge that offers but little resistance to the air. But 

 when a bird is somewhat pressed, it usually droops the wings 

 loosely, almost trailing them. And when in danger of being 

 caught by dogs, or struck by the bolas of a horseman, it 

 begins to dodge and twist in a very curious manner, the wings 

 assuming various positions. It would seem as though the wings, 

 thus used, may help the bird to make its sudden halts and turns; 

 and also, when dogs are used in the chase, to baffle the attacks 

 of these enemies. It was very curious to see the "tame" 

 ostriches indulging in these freaks even when unpursued by the 

 dogs of the estancia. The birds would rush straight along, turn 

 and twist, contort their necks into very comical shapes, jump, 

 and not unfrequently tumble over in their efforts to perform 

 some unusually complicated evolution. 



I may add that in the course of some years of "ostrich- 

 running," my brother once observed a troop of these birds swim 

 a river that crossed their path. He himself followed, and found 

 that the river was really out of their depth ; they were not 

 wading. 



(2) Snakes : the "J'izwa de la Cruz."— On October 6, 1888, 

 we came across one of these common poisonous snakes, probably 

 not long roused from its winter torpor. The dogs stood round 

 it barking ; and it remained, threatening a strike. With its tail 

 (and against the grass ?) it made a very distinct though not a loud 

 burring, vibrating sound. This, my brother told me, was usual. 

 Yet there is no kind of " rattle " on the tail. 



At the end of March 1889, after I had returned to England, 

 my brother killed a large vivora de la cniz ; and, observing that 

 it appeared to be very thick in the body, he cut it open in order 

 to examine it. Inside was a string of transparent bags, six or 

 seven in number, connected with one another. In each of 

 these could be seen a fully-formed young snake, about 6 inches 

 long, as far as he could say without exact measurement, coiled 

 up. Two of the bags he cut open ; and the young snakes, 

 released, both threatened to strike anything that approached 

 them, and made, though of course on a very small scale, the 

 vibrating, burring noise with the tail. 



NO. 1074, VOL. 42] 



(3) The Intelligence {?) of Anls.— One kind of small ant, if 

 not more, makes large nests underground, in the shorter grass. 

 A network of paths, clear of grass, about 2 inches wide near 

 the nest, converge towards this latter ; being the roads by which 

 the anis bring home forage. These paths are of all lengths 

 from ID yards up to 100 yards; and, as one tracfs them 

 further from the nest, they break up into smaller branches and 

 are tinally lost. As a general rule, one may say that streams of 

 ants carrying leaves, buds, flowers, seeds, and other valuable 

 odds and ends are always moving towards the nest, while empty- 

 mouthed ants are meeting and passing them on their outward 

 journey to the foraging grounds. Having, however, noticed a 

 few burdened ants proceeding with great difficulty against the 

 general stream of their burdened fellow- citizens, I tried the 

 experiment of turning some of these carriers round when they 

 had nearly reached home. The general conclusion I came to 

 was that these ants did not then understand in what direction 

 the nest lay, nor did they (as far as I could see) draw any con- 

 clusions from the fact that they now met the stream of carriers 

 with which they had previously been travelling. 



Thus, one ant, carrying a (relatively) huge burden, I reversed 

 in direction when already near the nest. I then followed it for 

 about 8 yards (or about 20 minutes of time as far as I can 

 say) in its mistaken reversed course away from the nest. Though 

 it met and collided with quantities of burdened ants, and was 

 passed in the same direction as its own by unburdened ants only, 

 it did not seem to take the hint. Its final return home was the 

 result of accident, as far as I could tell ; it having got up " the 

 right way round" after a severe fall. 



Still it must be noticed that among the undisturbed ants very 

 few went the wrong way. 



I dug a hole in one of the paths, on several occasions. The 

 hole was small ; and it was easy, though not so convenient, to go 

 round by the side over the very short grass. Nevertheless it 

 required the falling of very many ants into the hole, and the 

 leaving of quite a pile of leaves there, before the stream learned 

 to pass about about one inch to one or other side, and so to 

 avoid the pitfall. Some ants even turned back ; and I left them 

 carrying their burdens back to the foraging grounds again. 



(4) Grasses. — I noticed two grasses concerning whose seeds a 

 remark or two iray be of interest. 



(a) One is called " Tlechilla." Its seed bears a very sharp 

 point ; and a number of hairs, turned back from the point, 

 prevent the return of the seed from any body into which it 

 has penetrated. Attached to the seed is always a piece of stem 

 curiously twisted like rope. The whole answers somewhat to 

 an arrow-bead with barbed point and with shaft attached. My 

 brother, whose observations extend over more than twenty years, 

 tells me that this seed penetrates into the bodies of sheep, and 

 is found in their internal organs. The spring lambs, which 

 are left unshorn until summer is over, are especially troubled with 

 the flechilla. When one of these animals dies and is skinned, 

 it is very commonly found that quantities of these seeds have 

 penetrated the skin, the heads being found in the flesh under- 

 neath ; and my brother has found them in the liver. It is 

 believed that this is the cause of some deaths among the 

 animals. 



(j8) Another remarkable grass is the " Paja voladora." 

 This grows in tuffs, not unlike those of a small " Pampas 

 grass." From slender stems there stand out still slighter 

 branches, at the end of which are the seeds ; the whole, stem 

 and seeds, having somewhat the appearance of a miniature fir- 

 tree as regards shape, and having various leni;ths up to 2 feet or 

 so. When ripe, these stems with the seeds blow bodily away in 

 the first strong wind. I have seen them flying through the air, 

 looking from afar rather like a dust-cloud against the sky ; and 

 half rolling, half drifting, over the living giass of the plairi, 

 before the sudden onset of a tormenta (storm with wind). This 

 drifting movement over the grass had a curiously bewildering 

 effect on the eye. When the storm is over, the grass is found 

 in drifts against the posts and wires of the fences ; these col- 

 lections remind one strongly of snow-drifts. 



On December 16 (or so), 1888, a terrible accident occurred 

 on the railway between Candalaria and Guardia de la Esquina. 

 A cutting had become filled with this Paja voladora ; and the 

 engine set fire to it as it passed. However, thanks mainly to a 

 suitable wind, the train got safely through. But in the afternoon 

 of the same day the train re-passed in the opposite direction, 

 and the cutting had in the meantime become filled again with 



