264 



NATURE 



\Jan. 18, 1877 



be produced by the presence of the fungus. {Proc. R. Irish Acad. , 

 Vol. ii., Series ii. Science, January, 1877.) 



CoMMENSALiSM AMONG CATERPILLARS.— The following ex- 

 tract from a letter from Fritz Miiller, dated Itajahy, Brazil, 

 October 22, has been sent us by his brother, Dr. Hermann 

 Miiller, of Lippstadt : — "I have lately become acquainted with 

 an interesting case of commensalism in two caterpillars, of which 

 I inclose a photograph taken by my friend, Scheidemantel. 

 The larger caterpillar, with red head, protected by long 

 branchy stinging-hairs or thorns, lives on mulberry and other 

 trees. Like other caterpillars protected from enemies by odour, 

 stinging-hairs, or otherwise, it sits on the upper side of the 

 leaves, and is light-coloured, the head red, the hairs white. 

 Across its back, between its thorns, there sits a small blackish 

 caterpillar, protecting itself by the thorns of the large com- 



panion. I took off the small caterpillar from the large one, 

 but it soon occupied again the same place. In order to take a 

 photograph of it, the larger caterpillar was anaesthetised with 

 ether ; it recovered again somewhat, but after two days it 

 died. The smaller caterpillar has now left its place and taken 

 refuge on another caterpillar in the same box ; on this it 

 sits somewhat further forward, on the base of the abdomen. In 

 its former host, the place where the small caterpillar sat looks 

 pale, as if it had been scoured. The small caterpillar from 

 above eats small holes in the leaf on which the larger one is 

 sitting. As far as I know, no similar case has hitherto been 

 observed." 



Blistering Beetles as a Cure for Hydrophobia. — M. 

 de Saulcy, pere, laid before a late meeting of the Entomological 

 Society of France the debris of two species of beetles belonging to 

 the Meloidae {Meloe tuccius and Mylabris tenebrosd) which had 

 been sent to him from Gabes, in Tunis, by M. de Chevanier, and 

 which constituted the medicine in use by the people of Amerna 

 as a cure for hydrophobia. It is known under the name of 

 Dernona, and is mentioned in several Arabian works on medi- 

 cine. A portion about the weight of a grain of corn is given to 

 the sufferer. The medical formula directs that it should be taken 

 in some meat soup by the person bitten between the 21s'; and 

 27th day after the bite ; if taken before or after these dates it 

 will not effect a cure. The natives of Amerna seem to have 

 great faith in this cure, and preserve the dried beetles as a trea- 

 sure. It might be worth while to try a series of experiments on 

 the use of the vesicating beetles in this terrible malady. But it 

 should not be forgotten that so long ago as 1750, Linnseus, in 

 his uiboC^ti-^n. " De Materia Medica in Regno Animali, ' sug- 

 gested the employment in such cases of the common blistering 

 beetle, and in 1856, when M. L. Fairmaire laid before the Ento- 

 mological Society of France a brochure by M. Saint Hombourg 

 on the treatment of hydrophobia by the administration of a 



species of Melbe, many of the members then present men- 

 tioned that this remedy was known for a very long time in 

 Germany. {Ann. Soc. Ent. France, 27 Dec, 1875, Bulletin, p. 

 clxiii. ) 



Carboniferous Amphibia in Nova Scotia. — In the Car- 

 boniferous era many of the Sigillarian trees became partly 

 embedded, and as they decayed their inner bark and woody axes 

 crumbled away, leaving open holes on the surface of the ground 

 into which were swept by water, or fell accidentally, the animals 

 of the period together with vegetable debris. In this way suc- 

 cessive layers of deposit, within the trunks of the trees, became 

 stored with skeletons of Amphibian animals, snails, &c., 

 which they have retained in an admirable state of preser- 

 vation. Dr. J. W. Dawson, whose former investigations on this 

 subject are well known by all palaeontologists, has recently exa- 

 mined a fresh tree-stump about 2 feet high and 18 inches in 

 diameter. In its interior were found no less than thirteen skele- 

 tons, more or less complete, belonging to six species, including 

 Hylerpeton dawsoni, Dendrerpeton acadianum, D, oweni, a 

 new species of Hylerpeton and Hylonomus lydli. In the last 

 part of the American jFournal of Science and Art, Dr. Dawson 

 has described these remains. 



Action of the Brain. — At a recent seance of the French 

 Academy, MM. Giacomini and Mosso presented the photograph 

 of a woman who, from a syphilitic affection of the cranial walls, 

 had lost a great part of the frontal and the two parietal bones. 

 The movements of the brain of this woman (who is now com- 

 pletely cured) had been studied by the graphic method, one of 

 M. Marey's tambours having been applied at the cranial aper- 

 ture, and some remarkable results were obtained. The traces, 

 which will appear in the Archivio delle Science mediche, prove that 

 there are in the brain of man, even during the most absolute re- 

 pose, three different kinds of movement : — I. Pulsations, which are 

 produced at each contraction of the heart ; 2. Oscillations, which 

 correspond to the movements of the respiration ; 3. Undulations, 

 which are the largest curves, and are due to movements of the 

 vessels during attention, cerebral activity, sleep, and other 

 causes unknown ; they might be called spantaneous movements 

 of the vessels. The authors studied the relations between the 

 movements of the brain, the heart contractions, the changes of 

 volume of the forearm and the respiratory movements, by apply- 

 i)ig simultaneously with the arrangement just described, a pneu- 

 mograph to the chest, and one of M. Mosso's plethysmographs 

 to the forearm. The form of the brain-pulsation differs con- 

 siderably from the tracing obtained from the fore-arm, or by 

 means of a sphygmograph applied to an artery. During pro- 

 found sleep, with snoring, there is considerable increase in the 

 height of the cerebral pulsations, and the respiratory oscillations 

 and the undulations are much more pronounced. Certain causes 

 produce the same change of volume in the brain and in the 

 extremities ; others produce variations which are simultaneously 

 in opposition in the brain and in the different parts of the body. 

 The authors describe the effects of compressing the carotid and ' 

 the jugular, the influence of bodily movements and intellectual 

 labour, which are always reflected in a change of volume of the ■ 

 brain and therefore of its pulsations, and a number of interesting 1 

 facts are elicited, ' 



Papuan Plants, —So much still remains to be learned regard- 

 ing the natural productions of New Guinea, that Baron von, 

 Mueller's Descriptive Notes on Papuan Plants, will contain 

 much that is new to all botanists. Three successive papers have 

 now been published under this title, the material being chiefly 

 derived from the explorations of Macfarlane, Goldie, and D'Al- 

 berlis. Von Mueller hopes that one or other of these energetic 

 discoverers will shortly reach the hitherto unknown Alpine 

 heights, which are likely to yield rich stores of endemic species. 



