Dec. 20, 1888] 



NATURE 



Ql 



from a pine wood in Surrey ; also melanic forms of Torlrix fodana, 

 S. — Prof. Meldola, K.R.S., exhibited, for Dr. Laver, a melanic 

 specimen of Cati cala iiupta, taken last September at Colchester. — 

 Mr. E. B. Poulton exhibited preserved larva; of 5//»'«.rrt?«Z'f/j'w//, 

 showing the extreme dark and light forms of the species. — Mr. 

 McLachlan, F.R.S , called attention to a plate, rel)re^enling species 

 of the genus Agrolis, executed by photography, illustrating a me- 

 moir by Dr. Max Standfuss, in the Corrcspondcuz- Blatt, Verein 

 Iris, in Dresden, 1888. He considered it was the best example of 

 photography as adapted for entomological purposes he hid ever 



■n. — The Rev. Canon Fowler exhibited a specimen of Mycla-tis 

 ulionidfs, L., sent to him by Mr. OllitT, and taken near 



:ord about 1882. — Mr. W. Nicholson exhibited several 



;: clanic varieties of Argynnis niohc and A. pales, collected by 



himself last summer in the Engadine. — Mr. (. H. Leech 



\hibited a collection of Lepidoptera formed last year at 



.kiang. It included several new species. — Mr. H. Goss 

 ibited, for the Rev. T. A. Marshall, fifteen undescribed species 

 British Bracoitidie. — M. A. Wailly exhibited a collection 

 ; Lepidoptera lately received from Assam, containing upwards 

 ; thirty-five species o{ Papilio, Ornithoptera, Charaxes, Diadema, 

 I'yrestis, and other genera. — Mr. Meyer- Darcis exhibited speci- 

 mens of Stcrnocera tricolor, Kerr, and S. variabilis, Kerr, from 

 Lake Tanganyika ; and two new species oijitlodis from Syria. — 

 Mr. F. Merrifield exhibited, and made remarks on, a long series 

 oi Selcniaillustraria, S. illmtaria, 3.\.\dE. alniaria, in illustration 

 of his paper on " Pedigree Moth-breeding."— Lord Walsing- 

 ham, F.R. S., exhibited, and made remarks on, a series of species 

 representing the genera Snellenia, VVlsm., CEdanaiopoda, Z., 

 and Eretmocera, /.. — The Rev. T. A. Marshall communicated 

 a paper entitled "A JNIonograph of British Braconidie, Part 

 in." — The Kev. Dr. Walker communicated a paper entitled 

 '■ I>escription of a variety of the female of OrnithopUra 

 lirookiana." — Lord Walsingham read a paper entitled "A 

 Monograph of the genera connecting Tiutrg.ria, Wlk., with 

 Eretmocera, Z." A discussion ensued, in which Mr. Stainton, 

 F.R.S., and Dr. Sharp took part. — Mr. Merrifield read a paper 

 entitled " Incidental Observations in Pedigree Moth-breeding." 

 This paper contained a detailed account of experiments with 

 Selenia illiistraria, S. illunaria, and E. alniaria, which, so far 

 as they had yet proceeded, indicated that letardation of develop- 

 ment in the growing stages of the larvre, as well as in the pupal 

 stage, was the cause of the darkening of colour in the perfect 

 insects ; and that a low temperature had the effect of causing 

 such retardation. Lord Walsingham, Mr. Poulton, Prof. 

 Meldola, Mr. White, and Mr. Merrifield took part in the 

 discussion which ensued. — Mr. J. H. Leech read a paper en- 

 titled " Description of a small collection of Lepidoptera from 

 Kiukiang." Captain Elwes said he had examined this collection 

 with very great interest, and was struck with the similarity of 

 many of the species to those from Sikkim. 



Geological Society, December 5.— Dr. W. T. Blanford, 

 F. R.S., President, in the chair. — The following communications 

 were read : — Notes on two traverses of the crystalline rocks of 

 the Alps, by Prof. T. G. Bonney, F.R S These journeys were 

 undertaken in the summer of 1887, in the company of the Rev. 

 E. Hill, in order to ascertain whether the apparent strati.4raphical 

 succession among the gneisses and crystalline schists which the 

 author had observed in the more central region of the Alps, 

 held good also in the Western and Eastern Alps. At the same 

 time all circumstances which seemed to throw any light on the 

 ■"-icjin of the schists were carefully noted. The author examined 

 rocks along two lines of section : — (l) By the road of the 



i du Lauiaret from Grenoble to Brian^on, and thence by the 

 wunt Genevre and the Col de S'estrieres to Pintrolo, on the 

 margin of the plain of Piedmont. (2) From Lienz, on the upper 

 waters of the Drave, to Kitzbuhel ; besides examining other 

 parts of the central range, east of the Brenner Pass. The 

 specimens collected have subsequently been examined micro- 

 scopically. The results of the author's investigation may be 

 briefly summarized as follows: — (i) While rocks of igneous 

 origin occui- at all horizons among the crystalline series of the 

 Alps, these, as a rule, can be distinguished ; or, at any rate, 

 even if the crystalline schists in some cases are only modifietl 

 igneous rocks, these are associated with recognizable ignejus 

 rocks of later" date. (2) There are, speaking in general terms, 

 three great rock groups in the Alps which simulate curiously, 

 if they do not indicate, stratigraphical sequence. The lowest 

 and oldest resembles the gneisses of the Laurentian series ; the 

 next, those rather ' ' friable " gneisses and schists called by 



Dr. Sterry Hunt the Montalban s;ries ; the third and upper- 

 most is a great group of schists, generally lalher fine-grained, 

 micaceous, chloritic, epidotic, calcareous, and quartzose, passing 

 occasionally into crystalline limestones, and (more rarely) into 

 schistose quartzites. (3) The Pietra Verde group of Dr. Sterry 

 Hunt, so far as the author has been able to asceitain, consists 

 mainly of modified igneous rocks, of indeterminable date, and 

 is at most only of local, if, indeed, it be of any classificatory 

 value. (4) Of the above three groups the uppermost has an 

 immense development in the Italian Alps and in the Tyrol, north 

 and south of the central range. It can, in fact, be traced, 

 apparently at the top of the crystalline succession, from one end 

 of the Alpine chain to the other, (5) The middle group is not 

 seldom either imperfectly developed or even wanting, appearing 

 as if cut out by denudation. It was not seen in the traverse of 

 the Franco-Italian Alps, except perhaps for a comparatively short 

 distance on the eastern side, being probably concealed by 

 Palccozoic and Mesozoic rocks on the western side. It is not 

 very completely developed in the Eastern Tyiol, and seems to 

 prevail especially in the Lepontine Alps, and on the southern 

 side of the watershed. (6) The lowest group is fairly well 

 exposed, both in the French Alps and in the Central Tyrol. 

 (7) As a rule, the schists of the uppermost group had a sedimen- 

 tary origin. The schists and gneisses of the middle group very 

 probably, in part at least, had a similar origin. In regard to 

 the lowest group it is difficult, in the present state of our 

 knowledge, to come to any conclusion. (8) The slates and other 

 rocks of clastic origin in the Alps, whether of Mesozoic or of 

 Palaeozoic age, though somewhat modified by pressure, aie 

 totally distinct from the true schists above mentioned, and it is 

 only under very exceptional circumstances, and in very restricted 

 areas, that there is the slightest difficulty in distinguishing 

 between them. The evidence of the coarser fragmental material 

 in these Palaeozoic and later rocks indicates that the gneisses 

 and crystalline schists of the Alps are very much more ancient 

 than even the oldest of them. (9) The remarks made by the 

 author in his Presidential address, 1S86, as to the existence of 

 a "cleavage-foliation" due to pressure, and a "stratification- 

 foliation" of earlier date, which seemingly is the result of an 

 original bedding, and as to the importance of distinguishing 

 these structures ^generally not a difficult thing), have been most 

 fully confirmed. He is convinced that many of the contradic- 

 tory statements and much of the confusion in regard to the 

 origin and significance of foliation are due to the failure to 

 recognize the aistinclness of these two structures. In regard to 

 them it may be admitted that sometimes "extremes meet," and 

 a crystalline rock pulverized in situ is very difficult to separate 

 from a greatly squeezed fine-grained sediment ; but he Lelieves 

 these difficulties to be very local, probably only of a temporary 

 character, and of little value for inductive purposes. After the 

 reading of this paper, the author's conclusions were discussed 

 ) by the President, Mr. Teall, Dr. Hicks, Mr. Bauerman, Prof. 

 Blake, and Dr. Geikie. — On fulgurites from Monte Viso, by 

 Frank Rutley. — On the occurrence of a new form of tachylyte 

 in association with the gabbro of Carrock Fell, in the Lake 

 District, by T. T. Groom. Communicated by Prof. T. 

 McKenny Hughes. 



Paris. 

 Academy of ScienccF, December 10. — M. Daubree in the 

 chair. — Observations of Faye's comet, made at the Marseilles 

 Observatory, with the o'8o m. Foacault telescope, by M. 

 Stephan. These observations cover the period from December 

 5-8, when the nucleus was equal to a star of the eleventh or 

 twelfth magnitude. — Geographical work in Brazil, by M. L.Cruls. 

 The Imperial Observatory of Rio de Janeiro having undertaken 

 to determine the geographical positions of a number of stations 

 on the railway between the capital and Sahara, the results are 

 given for the first two stations of Rodeio and Entre-Rios. — On 

 the application of the theta functions of a single argument to the 

 problems of rotation, by M. F, Caspary. A rimmi\s given of 

 the calculations which the author has worked out with a view 

 to determining the formulas relative to the problem of rotation 

 of a heavy body suspended at a point of its axis. — On a general 

 proposition regarding linear equations with partial derivatives of 

 the second order, by M. Emile Picard. — On the employment of 

 oxygenated water for the quantitative analysis of the metals of 

 the iron group : (i) chromium, by M. Adolphe Carnot. On the 

 solutions of various metals of the iron group oxygenated water 

 determines certain reactions, sometimes of a reducing, sometimes 

 of an oxidating, character. This property is capable of being 



