cartilaginous rod, which runs from the tip of the tail to a point near the middle of the head, and round this, which is called the "notochord," bones and muscles develop. It is however an essential and most important feature in vertebrates, that by the rising-up and closing-in of the walls of the body above this notochord a tube is formed, which becomes the great cerebro-spinal nerve-organ, whilst below this axial rod the viscera and blood-vessels lie in a second tube, formed by the closing-in of the walls of the body below the notochord. Now it is a very remarkable fact that the nervous system in these young Ascidians is seen to lie over the gelatinous rod which runs along their tails, whilst the heart and viscera lie below it. The mode of formation of the nerve-system as described by Kowalevsky and Kupffer is the same as that seen in Vertebrata, that is, there is a rising-up of the embryonic walls to enclose a cavity, and though this part of the observations is not quite definite, it certainly appears as a long fusiform vesicle, which stretches its length through the embryonic Ascidian, being connected with a much larger vesicle anteriorily. It does not seem improbable to the believers in evolution that these structures in the embryo Ascidian represent some distant connection in development between them and the Vertebrata. More has to be looked for on this matter, and it is a subject for congratulation that the same brilliant observer, M. Kowalevsky, who has drawn attention to these facts as to Ascidians, should in the same year have furnished us with a most valuable account of the development of the lowest vertebrate, viz. Amphioxus, the history of which was previously unknown. The Significance of Cranial Characters in Man.-Professor John Cleland (spoken of by mistake in our report of the British Association Meeting as Professor McClellan) has communicated to the Royal Society a paper in which he gives an account of some careful investigations into the cranial measurements of various races, and criticizes the various methods of craniometry in usepointing out what facts of growth and relation of parts the observed measurements really indicate. He observes that if the terms dolichocephalic and brachycephalic are to retain any scientific value, as applied to skulls, the "cephalic index" (that is, the breadth in terms of the length which is called 100) must not be depended on. Other points of importance, as pointed out by Retzius, must be attended to. According to Dr. Cleland, the relation of the height to length of a skull is of great importance. There is no foundation whatever for the supposition, which is a wide-spread one, that the lower races of humanity have the forehead less developed than the more civilized nations; neither is it the case that the forehead slopes more backwards on the floor of the anterior part of the brain-case in them than it does in others. Diatom Markings and Podura-scale Markings.-The Rev. J. B. Reade, by the use of a very admirable reflecting medium, viz. a prism-constructed by Mr. Highley, of London-has been able to demonstrate satisfactorily that the so-called hexagonal markings of diatoms are, as Mr. Wenham had previously urged from investigating splintered bits of diatom-valves, simply hemispherical close-set tubercles. Dr. Royston Pigott, of Halifax, had, curiously enough a little before Mr. Reade, come to the conclusion that the well-known markings of the Podura-scale are caused by a series of spherical "beads" placed in the substance of the scale, which so act on the light as to produce the effect known to all microscopists. Dr. Royston Pigott has examined the subject with exceeding care, having had a th especially constructed for his use, and availing himself of great mathematical knowledge in discussing the optical problems involved. Literature. The reader is reminded of the Record of Zoological Literature', part of which is now ready, and which to increase its usefulness is now brought out in three separate volumes, so that those interested in a special department may obtain a complete and reliable record of what has been written concerning it during 1868, without being encumbered by other matter.M. Pollen, with the aid of several illustrious Dutch professors of Natural History, is publishing at Leyden an elaborate work on The Fauna of Madagascar and the neighbouring Islands,' where he spent some years exploring and collecting.-A new work by Mr. Darwin, 'On Man,' is stated by 'The Academy' to be in preparation. Memorial to Dr. Sharpey.-A physiological laboratory and scholarship and a portrait and bust of Dr. Sharpey are now being subscribed for by old and present students of University College, London, and by others interested in physiological research, and who value the teaching and influence of Dr. Sharpey in this country; the object of the subscription being to do honour to Dr. Sharpey, and to form a species of testimonial or memorial to him. There is not in England a single laboratory of experimental physiology properly worked and used for the education of students. It is to be hoped that the proposed Sharpey laboratory may form an example to be followed elsewhere. A distinguished German physiologist lately observed upon the strangeness of the fact, that in England we produce absolutely no physiologists in the strict sense. This may be due to the want of laboratories, which are provided by the State in other countries. Quarterly List of Publications received for Review. 1. The Life and Letters of Faraday. By Dr. Bence Jones, Secretary of the Royal Institution. 2 vols. Illustrated. Longmans, Green, & Co. 2. Elements of Chemistry: Theoretical and Practical. By William Allen Miller, M.D., L.L.D., V.P.R.S. Fourth Edition, with Additions. Part III., Organic Chemistry. Longmans, Green, & Co. 3. Exercises in Practical Chemistry. By A. G. Vernon Harcourt, M.A., F.R.S., and H. G. Madan, M.A., F.C.S. Series I. Qualitative Exercises. Clarendon Press. 4. Essays on Physiological Subjects. By Gilbert W. Child, M.A., F.L.S., &c. Second Edition, with Additions. Longmans, Green, & Co. 5. Twelve Lectures on Primitive Civilizations and their Physical Conditions. By John P. Mahaffy, A.M. Longmans & Co. 6. The Science of Arithmetic: a Systematic Course of Numerical 7. The School Arithmetic. By James Cornewell, Ph.D., and J. G. 8. Studies of the Land and Tenantry of Ireland. By B. Samuelson, M.P. Longmans, Green, & Co. 9. A Practical Treatise on Metallurgy, adapted from the last German Edition of Professor Kerl's Metallurgy. By William Crookes, F.R.S., &c., and Ernst Röhrig, Ph.D., M.E. Fuel, Supplements. With 145 Woodcuts. Vol. III. Steel, 10. Chemistry for Schools. By C. Houghton Gill, Assistant-Examiner in Chemistry at the University of London. 11. Burton-on-Trent. With 100 Illustra- Its History, its Waters, and its Breweries. Trübner & Co. By William Molyneux, F.G.S. 12. Index to the Fossil Remains of Aves, Ornithosauria, and Reptilia, from the Secondary System of Strata. Arranged in the Woodwardian Museum, Cambridge. By H. G. Seeley. VOL. VII. Cambridge: Deighton, Bell, & Co. L 13. The Rise and Progress of Manufactures and Commerce, and of Civil and Mechanical Engineering in Lancashire and Cheshire. By William Fairbairn, C.E., LL.D., F.R.S. (now Sir William Fairbairn, Bart.). PAMPHLETS AND PERIODICALS. Mineral Statistics of the United Kingdom for the Year 1868. By Robert Hunt, F.R.S., Keeper of the Mining Records. (Memoirs of the Geological Survey.) Longmans. By The Triassic and Permian Rocks of the Midland Counties of England. A Trip to America. By James Howard, M.P., Bedford. The Alexandra College, Dublin. Programme and Synopsis of Lectures to Ladies. (Three Pamphlets.) On the Continuity of the Gaseous and Liquid States of Matter. By Thomas Andrews, M.A., F.R.S. Bakerian Lecture. Methods of Teaching Arithmetic. By J. G. Fitch, M.A. Stanford. Introductory Address delivered at the Royal Infirmary School of Medicine, October 1st, 1869. By A. Davison, M.A., M.D. Liverpool: Adam Holden. The Working Man's School. By W. J. Kennedy, M.A. Longmans. The Popularity of Error and the Unpopularity of Truth. By John Hampden, Esq. A Brief Paper on the Pathology of Insanity. By R. C. Shettle, M.D., Physician to the Royal Berks Hospital. The Canadian Naturalist and Geologist. (With the Proceedings of the Natural History Society of Montreal.) The Liverpool Medical and Surgical Reports. Edited by P. M. Braidwood, M.D., and Reginald Harrison, F.R.C.S. The Geological Magazine. The British and Foreign Mechanic. The Quarterly Journal of Microscopical Science. J. Churchill & Sons. Revue Bibliographique Universelle. Cosmos. Journal of Applied Chemistry, published simultaneously in New York, Philadelphia, and Boston. The American Naturalist. Van Nostrand's Eclectic Engineering. The Gardener's Magazine. The Civil Service Gazette. The Westminster Review. PROCEEDINGS OF LEARNED SOCIETIES, &c. Öfversigt af Kongl: Vetenskaps-Akademiens Förhandlingar. |