140 feet wide; a fine promenade, 560 feet long by 50 feet wide, leads to the pier head., which is 310 feet long by 140 feet wide. The pier head has an area of 39,000 feet, and at each end of its four corners is an ornamental tower, two similar edifices adorning the abutments also. The Cincinnati Suspension Bridge is rapidly approaching completion. Its total length, including the approaches, will be 2,252 feet; length of main span from centre to centre of the towers, 1,057 feet; length of end spans, 281 feet; width of bridge in the clear, 36 feet; and height above low water, 100 feet. It is supported by two cables of 12 inches diameter, made up of 7 strands, each of which contains 740 wires. The floor beams are of wrought iron; two iron trusses, 10 feet high, will separate the footways from the carriageways, and an ornamental iron railing will protect the foot passengers on either side. Wrought-iron girders, 30 feet long and 12 inches wide, will run the entire length under the middle of the bridge. 7. ENTOMOLOGY. (Including the Proceedings of the Entomological Society.) IN 1863 the Linnean Society published the first part of a memoir by Sir John Lubbock, "On the Development of Chloëon dimidiatum." The second and concluding part of that memoir has just appeared in the twenty-fifth volume of the Society's 'Transactions, p. 477. It is generally believed that all insects, with few exceptions, pass through three definite stages of existence after leaving the egg; but in the case of Chloëon there are no such stages; instead we have a series of gradations. It is true that the Ephemeridæ, the family to which Chloëon belongs, have been long known to have their metamorphoses incomplete, but we are indebted to Sir J. Lubbock for a definite account of their various changes. The condition in which the young Chloëon leaves the egg is uncertain, but the smallest specimens being only 18-800ths of an inch in length, and quite colourless and transparent, it is assumed that these are in their "first state." From this point there are not less than twenty states (or moultings), through which the insect progresses before it leaves the water, in which it has hitherto passed its life, to assume the "proimago" form, and this differs apparently from the perfect insect chiefly in certain peculiarities of the wings and legs. It is quite impossible here to follow the various changes which are minutely detailed in the two memoirs; we can only observe that it is not until the eighteenth stage that the external sexual characters of the males begin to show themselves, and that in some of the stages a sort of retrograde movement takes place. It is one of the conclusions of the author that "external forces" acting on the larva produce those changes in the organization which have reference to its immediate wants rather than to its final form, and this, he thinks, accounts for "those cases in which animals, very similar in their mature condition, are very unlike in their earlier stages." In reference to "dimorphism" or "polymorphism," Sir J. Lubbock would confine the term to the cases of those animals or plants which "preserve themselves at maturity under two different forms," as in Ants and Bees: the "differentiating action of external circumstances, not on the mature but on the young individual," resulting in another series of phenomena, many of which have been described under the name of alternation of generations, he would distinguish by the term "dieidism" or "polyeidism." A discussion on the nature of Pebrine (the silk-worm disease) has been recently carried on in the Comptes Rendus' between MM. Becamp, Joly, and Pasteur. The last-named author believes the "vibratory corpuscules" (one of the peculiarities of the disease) to be pathological productions analogous to the globules of pus, or of the blood. M. Becamp, on the contrary, considered them to be of a vegetable nature. M. Joly had also observed in 1862 innumerable quantities of infusoria, which he described under the name of Vibrio aglaise mixed with the vibratory corpuscules; these corpuscules have since been stated to owe their origin to the Vibrio, but M. Joly denies this and asserts the Vibrio to be the effect and not the cause of the corpuscules. Of the origin of the disease nothing seems to be known, but, as a remedy, M. Becamp suggests the vapour of creosote, which, although it would not directly destroy the disease, would prevent the formation of spores by which the disease is propagated. The Zoological Society has recently published a paper by Mr. Pascoe, on the "Coleoptera of Penang," the writer attempts to show that "the area into which the earth's surface may be divided in relation to its organic productions, will not hold good for all classes, or even in some cases for all orders;' 'and that "so far as the Coleoptera are concerned, the Malayan region, with its centre in Borneo, finds its South-eastern limit in New Guinea, Australia constituting a very distinct and remarkable region of its own." Messrs. Lovell Reeve and Co. have issued another of their cheap works on Natural History; it is entitled, 'British Bees: an Introduction, &c.,' by W. E. Shuckard. It is remarkable for its "spirit of captiousness," and might have been written twenty years ago so far as most of its statements are concerned; indeed the author tells us that "from the length of time that has intervened," the "facts recorded have become so blended in his mind," that whether they are the result of his own observations, or of "diligent study" (of the observations of others ?) he "can no longer separate their sources." Mr. Roland Trimen, of Cape Town, has published the second part of his Rhopalocera Africæ australis (South African Butterflies), including the Satyridæ, Eurytelidæ, Lycænidæ, and Hesperidæ. PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY. Sept. 3.-Among the exhibitions was a small collection of Coleoptera from Jamaica made by Mr. Gloyne. In reference to the Ailanthus silk-worm, Prof. Westwood said that he had found wasps very destructive to the young caterpillars. Mr. Trimen communicated a paper on the Butterflies of the Mauritius. This portion of the fauna of that island appears to be of decidedly African origin, most of the species being identical with those found in South Africa and Madagascar. There were only twenty-five species. Mr. F, Smith read an account of a collection of Hymenoptera-mostly Bees-sent to him from Catagallo, in Brazil. It contained the female of Trigona, the male only of that genus having been previously known; in the gravid state their abdomens were enormously distended, and in this respect they bore a remarkable similarity to the same sex of the white Ants (Termes). In consequence of the new arrangement with reference to the Meetings of this Society at Burlington House, no meeting was held in October. Nov. 5.-Mr. Janson exhibited some rare Coleoptera from Tasmania. Mr. Stainton exhibited a collection of Tineina from Asia Minor and Syria. Some large galls from the elm, supposed to be formed by Aphides, were shown by Mr. F. Smith.. A singular case or covering of a species of Coccus, resembling a small limpet-shell (Patella), from Port Lincoln, was sent for exhibition by Mr. Angas. The President (Sir J. Lubbock) brought under the notice of the meeting specimens and drawings of a new Myriapod found in his grounds at High Elms; it was remarkable for its small size, and for having only nine pairs of legs; it was proposed to be called Pauropus. The Rev. Douglas Timins communicated a note "On the Habits of Argynnis Lathonia, in the north of France." Mr. M'Lachlan read a paper "On new Genera and Species of Psocida." Mr. E. Saunders read a paper, entitled "Descriptions of Six New Species of Buprestidæ, belonging to the Chalcophorides of Lacordaire." -- Nov. 19. Mr. Stainton exhibited drawings and specimens of the Stathmopoda Guerinii, bred from Aphides galls found on the Pistacia terebinthus, and sent by Dr. Staudinger from Celles-les Bains, in the Ardèche. This is one of the very few cases in which a moth is found as an inquiline of a gall; another such case Mr. Stainton stated comes to us from North America. Dr. Sharp exhibited seventy-one species of Coleoptera new to Britain, eleven of these, it was believed, were unknown on the Continent; descriptions of the new species were read. Mr. Meek exhibited an undescribed Noctua, taken at Bermondsey, and Dicrorhampha fulvo-dorsalis, taken in North Devon, and new to the British list. Prof. Westwood, in introducing the subject of an extraordinary hermaphrodite butterfly (Pieris Pyrrha), a drawing of which was exhibited, took occasion to make several observations on the Darwinian hypothesis. Mimetic forms, he considered, could only be looked upon as illustrations of the law of resemblance; he believed that all species were created with the same characters and attributes that they now possess, and consequently that there was no "relationship" between species even of the same genus, but that similarity alone constituted the bond of union. He was replied to by Messrs. Wallace and Bates, and a discussion ensued in which Dr. Sharp, and Messrs. M'Lachlan and Pascoe took part. 8. GEOGRAPHY. (Including the Proceedings of the Royal Geographical Society.) THE flow of geographical knowledge is something like that of that great river, which has at all times attracted and even is now attracting the principal attention of travellers-it is of an intermittent character. Occasionally an overwhelming flood pours down upon us, so that we are unable at the time to make full use of its fertilizing powers, and we have to wait until the waters have somewhat subsided before the seeds of rational theory can be sown upon the new alluvium. The present is rather the time of ebb. But few travellers have of late returned to these shores, and though much solid advance is being made by means of accurate descriptions and statistics, but little startling enterprise attracts the attention of those who are dazzled by hair-breadth escapes. In Abyssinia English captives still linger, though additional tidings and gradual steps towards their ultimate return are from time to time reported. The Europeans supposed to be held in captivity in Somali land, where they were cast by the shipwreck of the St. Abbs, are now being sought by a native, whose diligence has been stimulated by the promise of 1007. per head for all brought back in safety. The report now published, with maps, photographs, &c., of the Palestine Exploration Fund is of the character which we have described above, a solid increase to our knowledge of an already tolerably well-known country, but it contains no startling adventure to make it attractive to any but the scientific mind. The sites of forty-nine places of importance have been determined with accuracy, amongst these the exact position of the synagogue at Capernaum. The scenes of many events in the Old and New Testaments have been fixed, the main back-bone of the country been mapped out, besides photographs of natural objects, ruins, inscriptions, &c., prepared. Much light is likely to be thrown upon a subject as yet but little understood, viz. Semitic Palæography, of which several scholars are springing up. M. Terrell has sent a paper to the French Academy on the composition of the Dead Sea, in which he states that he distinctly saw small fish thriving well near the site of the ancient Sodom. The regions of Cambodia and Siam have been visited by Mr. J. Thomson, who has photographed many most interesting ruins of ancient cities and temples. An account of these was read before the British Association, and it is probable that a fuller narrative will appear before long of a very carefully undertaken and successful journey in search of almost unknown records of a forgotten civilization. In Australia it was reported that the remains of Dr. Leichhardt had been discovered by the exploring party fitted out for that purpose, but the news turns out to be unfounded. On the other hand, it appears that the leader of the expedition, Mr. Duncan McIntire, had died from fever, but the search was being continued under Mr. Campbell. The continent has again been crossed from Victoria to the Gulf of Carpentaria, but the main objects of the expedition are reported to have failed. We are now promised speedier intelligence by a new route to Australia-the natural one, via Panama. The journey outwards was very successfully performed, and New Zealand in particular reaps the benefit of the change; but the homeward mail, though starting a few days before the so-called overland mail, arrived in this country after its rival. A careful study of the ocean currents and the periodical winds may perhaps help to overcome some of the difficulties. One of these currents, the Gulf stream, is said by M. Grad to keep its identity beyond Spitzbergen and Nova Zembla into the Polar Basin, thus affording open sea far to the north of these islands, where an entrance must be sought by future travellers searching for the North Pole-a subject we have discussed in a former number. Slight alterations in the direction of this current, arising from the abrasion of rocks where it first enters the ocean, are from time to time reported, leading, we may suppose, to extensive changes in the effects on this side of the Atlantic. Similar changes VOL. IV. I |