44§ 



NA TURE 



[March 12, 1885 



like whey out of cheese, and it may finally consolidate as con- 

 temporaneous veins in the plutonic rock, as dykes in the sur- 

 rounding volcanic rocks, or as rhyolitic lavas and tuffs at the 

 surface. The ideas here thrown out appear to me to be capable 

 of extension to other volcanic regions ; but as the sequence in 

 these regions is generally complicated by the coming in of basic 

 rocks during the later phases of volcanic activity, it will not be 

 advisable to enter more fully into the subject on the present 

 occasion. 



The special characters which igneous rocks present, then, are 

 to be traced to the chemical and physical properties of the 

 original magma and to the influence of surrounding circum- 

 stances. Rocks, like minerals, are in a state of stable equi- 

 librium when subjected to the conditions of their formation. 

 When subjected to other conditions, whether physical or 

 chemical, they usually undergo a change. The destruction and 

 disintegration of igneous rocks by the various agents of denuda- 

 tion are familiar to every student of geology, and need not there- 

 fore be described on the present occasion. 



I trust I have now said sufficient to show that the science 

 of petrography is one of the greatest importance to the geologist 

 of the present day. The remarks on ^etiological petrography 

 are, of course, only intended to illustrate the nature of this 

 branch of the subject, and to show that conclusions of the 

 greatest theoretical interest may be expected to follow from a 

 careful consideration of the facts acquired by work in the other 

 branch of the science. 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE 



Cambridge. — A Report recently issued gives particulars of 

 the successful raising of the roof of the Mineralogical Museum 

 to form a Morphological Laboratory on the new floor thus 

 created. The firm of builders who had furnished estimates 

 ultimately declined the work, and the Department of Mechanism 

 undertook it. Under the continual superintendence of Prof. 

 Stuart and Mr. Lyon the work was so skilfully done that not a 

 crack was occasioned in the ceiling of the Mineralogical Museum, 

 and the deflection of the new timbers was so well calculated 

 that no timber moved upwards or downwards more than the 

 eighth of an inch when the load came upon it. The cost was 

 several hundred pounds less than the estimate. The roof raised 

 was no feet long, and the weight fifty tons. A special vote of 

 thanks is to be given to the Department of Mechanism for the 

 care, skill, and economy with which the building operations were 

 conducted. 



The Botanical Laboratory has cost a little over 800/. ; the 

 Morphological Laboratory has cost about 2500/. 



In the Natural Science "Special" Examinations for the 

 ordinary B.A. degree during the past year, the great majority 

 of candidates chose Chemistry, and showed that they had be- 

 stowed considerable pains on laboratory work while yet they 

 were only imperfectly acquainted with the rationale of the pro- 

 cesses they employed. The candidates in Botany had neglected 

 systematic, and especially descriptive, botany. In June the 

 descriptions of easy, well-marked specimens of flowering-plants 

 were so worthless, that it was difficult to find out, from some 

 descriptions, to which of the specimens they were intended to 

 apply. 



In Mechanism and Applied Science book-woi"k was satisfac- 

 torily done, but deductions and numerical applications were very 

 imperfect. Drawing was well done, and the candidates also 

 showed a practical acquaintance with the use of tools ; but 

 they did not sufficiently connect their mathematical with their 

 practical knowledge. 



In the previous examination or little-go, Jevons's logic was set 

 as an alternative subject to Paley with considerable success last 

 year. Out of forty-four candidates only six failed. In arith- 

 metic a knowledge of decimals and the use of common sense 

 were strikingly wanting. The gradual elevation of standard 

 in Euclid and Algebra of late years appears to have produced 

 beneficial results. The papers in Mechanics in the October 

 examination (on entrance) were unsatisfactorily answered ; the 

 candidates had for the most part read treatises dealing with the 

 subject incompletely and popularly. 



The proposal to discontinue entirely the additional examina- 

 tion in Mathematics for Honours Candidates has been rejected 

 by a large majority, it having been found impossible to provide 

 any substitute which would command general assent. 



Mr. M. C. Potter, Assistant Curator of the Herbarium, has 

 been approved as a Teacher of Botany. 



The Physiological class-rooms having again become seriously 

 overcrowded, owing to the increase of the medical school, a 

 scheme for building new class-rooms with a large lecture-room is 

 put forward by the Museums and Lecture Rooms Syndicate. 

 The lecture-room is to be 45 feet by 40, and 32 feet high, and 

 is calculated to accommodate 247 students comfortably. A 

 new class-room 80 feet long to accommodate 100 students 

 working at one time is an important feature, and rooms will also 

 be provided for Prof. Roy's temporary Pathological Laboratory. 

 The estimate cost is 9000.'. 



SCIENTIFIC SERIALS 



Journal of Anatomy and Physiology, January, contains : — 

 Diseases of the reproductive organs in frogs, birds, and mammals, 

 by J. B. Sutton (plate 8). — Oviduct in an adult male skate, by 

 J. D. Matthews (plate 9). — On the influences of some conditions 

 on the metamorphosis of the blow-fly, by J. Davidson. — On the 

 sources and the excretion of carbonic acid at the liver, by J. J. 

 Charles. — On a method of maceration, by A. M. Paterson 

 (plate 10). — Floating kidney, by D. Hepburn. — The movements 

 of the ulna in rotation of the fore arm, by Thos. Dwight. — Dis- 

 section of a double monster, by A. Hill. — Relation of the alve- 

 olar form of cleft palate to the incisor -teeth and the intermaxillary 

 bones. — The dumb-bell-shaped bone in the palate of Ornitho- 

 rhynchus compared with the pre-nasal bone of the pig. — The 

 infra-orbital suture ; and an additional note on the oviducts of 

 the Greenland shark, by W. Turner. — Anatomical notes. 



Quarterly Journal of Microscopical Science, January, con- 

 tains : — On the significance of Kupffer's vesicle, with remarks on 

 other questions of vertebrate morphology (plate 1), by J. T. 

 Cunningham. — Blastopore, mesoderm, and metameric segmen- 

 tation, by W. H. Caldwell (plate 2). — On the origin of the 

 hypoblast in pelagic teleostean ova, by G. Brook. — On the 

 pre-ence of eyes in the shells of certain Chitonidre, and on the 

 structure of these organs, by H. N. Moseley (plates 4, 5, 6). — 

 Archerina boltoni, nov. gen. et sp., chlorophyllogenous proto- 

 zoon allied to Vampyrella, by E. Ray Lankester (plate 7). — Cm 

 the apex of the root in Osmunda and Todea, by F. O. Bower 

 (plates 7 and 8). — Correction of an error as to the morphology 

 of iVelwitschia mirabilis, by F. O. Bower. — E. Van Beneden's 

 researches on the maturation and fecundation of the ovum, by 

 J. T. Cunningham (plate :o). — On the suprarenal bodies of 

 vertebrata, by W. F. R. Weldon (plates II and 12). — On the 

 life-history of certain British hetercecismal uredines, by C. 

 Plowright. — On the occurrence of chitin as a constituent of the 

 cartilages of Limulus and Sepia, by W. D. Halliburton. 



Journal of the Royal Microscopical Society, February, con- 

 tains:— On the apparatus for differentiating the sexes in bees 

 and wasps. An anatomical investigation into the structure of 

 the receptaculum seminis and adjacent parts, by F. R. Cheshire 

 (plates I and 2) — On the occurrence of variations in the deve- 

 lopment of a Saccharomyces, by G. F. Dowdeswell. — Notes on 

 the life-histories of some little-known Tyroglyphidse, by A D. 

 Michael (plate 3). — The usual summary of current researches in 

 zoology, botany, and microscopy. 



The American Naturalist, February, contains : — On the 

 habits of some Arvicolinre, by E. R. Quick and A. W. Butler. 

 — On a parasitic copepod of the clam, by R. R. Wright. — On 

 the rudimentary hind-limb of Megaptera, and on the finger- 

 muscles in M. Imgimana and in other whales, by J. Struthers. — 

 The structure and development of the suspensory ligament of 

 the fetlock in the horse, by J. D. Cunningham. — The Winooski 

 or Wakefield marble of Vermont, by G. H. Perkins. — A botani- 

 cal study of the mite-gall found in the black walnut, by Lillie 

 J. Martin. — On the evolution of the Vertebrata, progressive and 

 retrogressive, by E. D. Cope. 



Rendi onti del Real: Istituto Lombardo, January S. — Annual 

 report on the work of the Institute in the various^ branches of 

 science and letters during the past year, by the Secretary. — Bio- 

 graphical notice of Baldassare Poli, by Prof. Carlo Cantoni. 



January 15. — On the secular variations in the elements of ter- 

 restrial magnetism at Venice, by Ciro Chistoni. — On a rare case 

 of congenital malformation of the bladder, by Dr. G. Fiorani.— 

 Extent of the diurnal oscillation of the magnet of declination at 

 Milan in the year 1884, by Prof. G. V. Schiaparelli —On the 

 anatomy of the human brain, by Dr. Casimiro Mondino. — On 



