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SCIENTIFIC NEAVS. 



[April 20, iS 



along in the bush, what he took at first to be a very 

 large serpent, but which on closer inspection proved to 

 be a dense column of caterpillars more than twelve feet 

 in length. 



The European " processionaries " have never been 

 known to collect in such enormous numbers, but they 

 may justly rank among the most injurious insects known. 

 Not only do they occasion great damage in woods and 

 plantations, but their hairs, which are detached by the 

 slightest friction or even by the wind, are dangerous 

 both to man and to domestic animals. If they come in 

 contact with the hands or the face they occasion violent 

 irritations. If drawn into the mouth or nostrils serious 

 inflammation of the mucous membranes ensues, and 

 occasionally proves fatal. 



The remedies proposed for this affection, when ex- 

 ternal, have been tried by Dr. Champouillon upon him- 

 self. He finds that when the inflamed spots are few 

 and far between, relief is obtained on covering them 

 with crushed parsley. If the inflammation is more 

 general, baths of salt water or of carbonate of soda are 

 found useful. In attacking the nests of these caterpillars 

 it is advisable to advance from the windward, and to 

 keep the mouth and nostrils covered with a fine cloth. 



It is a curious but discreditable fact that the hairs of 

 such, and of similar caterpillars, have figured in the 

 annals of secret poisoning. We use the term " poison- 

 ing " with reservation, since it appears probable that the 

 injury occasioned by these hairs depends more on the 

 mechanical action, due to their barbed points, than on 

 any deleterious chemical principle present. 



The chief European species of this group are Cnetho- 

 campa processionea, which is found in France and the 

 south and west of Germany. It attacks oak woods in 

 the months of May and June, and often completely strips 

 them of their leaves, to the no small injury of the trees. 



Cnethocampa piiiivora commits similar havoc in the 

 pine-forests of Eastern Germany, the south of Sweden, 

 and the west of Russia. 



Cnctliocampa pityocanipa attacks the pine, and is more 

 dreaded than the oak-processionary. The reason for 

 this lies in the nature of the tree. If an oak be stripped 

 of its leaves in the early part of June it puts forth a 

 second crop about midsummer. But to a pine-tree the 

 entire loss of its leaves is generally fatal. 



The pityocampa haunts the woods of Southern France, 

 the Tyrol, and Illyria, and its hairs are more dreaded 

 even than those of the oak-processionary. In order to 

 destroy these pests, the cocoons are dragged down from 

 the trees by means of hooked sticks raked together 

 and burnt. 



Cats v. Rabbits. — According to the Australasian, the 

 domestic cat is really of practical value as a rabbit- 

 destroyer. It seems that Mr. F. W. Armytage has an 

 estate in Victoria of some 20,000 acres, which, like those 

 of his neighbours, was sorely infested with rabbits. The 

 extent of the infliction may be guessed from the fact 

 that, though the trappers sent away the skins of some 

 50,000 annually and many more thousands were killed 

 in battues, not to speak of their occasional destruction 

 by poison, the pest remained practically unabated. Then 

 it occurred to Mr. Armytage to try cats. He put a stop 

 to trapping, and in consequence was denounced as the 

 "poor man's enemy." He introduced a number of cats 

 — some three hundred or so — and the " poor man " con- 

 trived to destroy a third of the number. But those that 



were left did their work. A rabbit-proof fence pre- 

 vented an increase to the number of rabbits from with- 

 out, and the cats pretty well disposed of those within. 

 It is true they had for auxiliaries a man and a large 

 kennel of ferrets ; but, even with this help, the work 

 they did was very notable. In the 20,000 acres, it is 

 said, " the number of rabbits now left on the estate is 

 scarcely larger than Mr. Armytage would like to have, 

 as he is fond of having a few friends out for a day's 

 shooting." It was noticeable, too, that the cats had com- 

 mitted little depredation on the small birds, for these, 

 when " Bruni " visited the estate, were in abundance, 

 and singing merrily. Naturally the inference suggests 

 itself to the writer that, if cats could do such good work 

 in a comparatively limited estate in Victoria, they could 

 do much better in the large stations of Central Australia, 

 ■"vhere they would be free from their relentless enemy — 

 the rabbit trapper. 



The Sensitiveness of Plants. — Professor Baillon 

 has communicated to the French Linnean Society the 

 results of his experiments on the curvature of the tendrils 

 of Cissus discolor. The slightest friction applied to one 

 of the two branches of the tendril occasions on a few 

 moments a curve concave to the point rubbed. If both 

 sides of the tendril are equally rubbed, no flexion takes 

 place. These facts confirm the fundamental uniformity 

 of the substance which, alike in plants and animals, 

 forms the physical basis of life. The phytoblast is thus 

 of an animal nature, like the sarcode. Our readers will 

 recall how exactly this agrees with the conclusions of 

 Charles Darwin, who had experimented on the very 

 same plant, and who was of opinion that plants, e.g., the 

 Drosera, possess a substance analogous, at least in its 

 constitution and its functions, to nerve-matter. 



Poisonous Fishes. — An interesting feature in the 

 " Fisheries" Exhibition, now open at Havre, is a collec- 

 tion of poisonous fishes. A tehodon found in the 

 Japanese seas is so poisonous that it is sometimes used as 

 a means of suicide. The symptoms produced resemble 

 those occasioned by an overdose of morphia. 



Curiosities of the Senses. — According to a memoir 

 communicated to the Biological Society of Paris by M. 

 Mathias Duval, and reported in the Siecle, it is not ad- 

 vantageous when looking through a telescope with one 

 eye to close the other, but rather the contrary. We 

 have not succeeded in verifying this observation with the 

 microscope. 



Natural History of the Isle of Man. — Dr. P. Q. 

 Keegan (^Science Gossip) gives a very interesting sketch 

 of the geology, mineralogy, and botany of the Isle of Man, 

 but leaves its zoology untouched. 



Instinct of Birds. — Under this title the Journal of 

 Microscopy quotes a report that in Peru and other parts 

 of South America last year's fruit has been avoided by 

 birds, while it has caused the death of sheep and cattle 

 which fed on it in large quantities. These observations 

 have been cited as tending to show that the instinct of 

 birds, with respect to the wholesomeness of fruits is 

 frequently a worthy guide for human beings to follow. 

 The possibility is suggested that the variation in the 

 fruit of different years may have something to do with 

 the outbreak of cholera. 



