472 



NATURE 



{Sept. II, 1879 



Lepisma saccharina also feeds on paper, of which a very 

 curious example was exhibited of a framed and glazed print of 

 which the plain paper was eaten whilst the parts covered by the 

 printing ink were untouched. White ants, Termitidje, are a 

 constant source of annoyance in warm climates ; and Prof. 

 Westwood also noticed the ravages committed by the cockroaches, 

 Blatta orientalis. 



The insects that do the greatest injury are Anolium pertinax 

 and A. striatum, commonly known as the death watches, burrow- 

 ing through the books, even, it is recorded, drilling through 27 

 folio volumes. 



Various remedies for the destruction of these insects were 

 mentioned and especial notice was directed to a "Report of 

 the Commission appointed to inquire into the Decay of Wood- 

 Carvings, and the Means of Preventing and Remedying the 

 Effect of such Decay," issued by the Science and Art Department 

 in 1864. 



Prof. Westwood then detailed the various remedies proposed, 

 as washing with solution of corrosive sublimates in alcohol, ex- 

 posing the books to the vapour of benzine, or carbolic acid, or 

 hydrocyanic acid, or fumigating with burning sulphur. Placing 

 the volumes under the exhausted receiver of an air pump for an 

 hour, has been found successful by Dr. Hagen. 



The Occurrence of Leptodora in England. — Sir John Lubbock 

 called the attention of the Section to the occurrence in England 

 of Leptodora, a very interesting crustacean first found in deep 

 lakes abroad, and more recently in a reservoir near Birmingham. 

 Like many marine organisations it was as transparent as glass. 

 This rendered the creature less conspicuous to its foes. Like 

 other animals of the same group it laid two kinds of eggs. The 

 young at first were quite unlike their parents, so unlike that they 

 had been thought to be a distinct species. Sir John then entered 

 into a description of the little animal, and by means of sketches 

 illustrated the peculiar functions of the different organs, pointing 

 out the difference of the organs in male and female. 



On the Homologies of the Cephalopoda, by J. F. Blake. — The 

 flexure of the intestine in Cephalopoda and Pteropoda is " pedal," 

 and that of other Odontophora, " cephalic ;" and the body of 

 a cephalopod must be placed with the mantle cavity horizontal 

 for comparison with a gastropod. The arms are not homologous 

 with the foot, but form an "antivelum." The labial and 

 tentacular processes, and not the individual tentacles of a 

 Nautilus are shown to be homologous to the arms of an 

 Octopod. The hood is associated with the aptychus of the 

 Ammonite, the shell of an Argonaut, and the neckplates of a 

 Sepia. The Ascoceras is cited to show the relations of the 

 sepia-bone to the nautilus shell. 



On Cyclops, by Marcus M. Hartog, M.A., B.Sc. — The 

 nervous-cord of Cyclops is essentially copepodan in type, it 

 is not dilated into special ganglia, and contains no cellular 

 elements beyond the third thoracic segment. It bifurcates 

 in the second abdominal segment, and the branches terminate 

 in the furca. The sensory and motor nerves appear to be wholly 

 distinct, the latter coming off at a higher or deeper level. All 

 the sensory nerve -fibres pass through a bipolar ganglion cell near 

 their distal termination. Minute rounded spaces in the hypoderm, 

 especially one at the base of the last thoracic limb, appear to be 

 auditory organs. Respiration in Cyclops is entirely anal. 



On Mimusopea, a Section of the Order Sapotacea:, by Marcus 

 M. Hartog, M.A., B.Sc. — In this paper the genus Dipholis is 

 merged in Bnmelia, and the genera Imbricaria, Labramia, and 

 Muriea in Mimusops : a review of the deferential characters 

 hitherto relied on showing their inadequacy from every point of 

 view — even convenience. 



On Fruits and Seeds, by Sir John Lubbock, St., V.P.R.S. 

 M.P. — Sir John commenced by calling attention to the difference 

 presented by seeds, some being large, some small, some covered 

 with hooks, some provided with hairs, some smooth, some sticky, 

 &c., and after observing that there were reasons for all these 

 peculiarities, proceeded to attempt to explain some of the more 

 striking. In the first place, he said, many seeds required pro- 

 tection from birds and insects ; hence the shells or husks of 

 the beech, Spanish chestnut, horse chestnut, walnut, &c. In 

 some cases, as in the common herb Robert, the calyx, or outer 

 envelope of the flower opens, when the flower expands, and 

 closes over the seeds when the flower fades, and o] ens again 

 when the seeds are ripe. In other cases the flower-st.ilk changes 

 its position. Thus in the dandelion, it is upright when in 

 flower, lies close to the ground after the flower has faded, and 

 rises again when the seeds are ripe. In the cyclamen again, the 



flower-stalk curls itself up into a spiral after the flower has 

 faded. 



He then called attention to the modes of dispersion by means 

 of which seeds secure a sort of natural rotation of crops, and are 

 also in other cases enabled to rectify their frontiers. Some 

 plants actually throw their seeds. Thus in the common carda- 

 mine, the outer membrane of the pod becomes very tense, and 

 when ripe, at the least touch it gives way at the base, and curling 

 up with a spring throws the seeds three or four feet. The 

 common geraniums also throw their seeds, and so do some of 

 the cucumbers, but in these cases the mechanism is different. 

 He then described the curious "elaters" of the equisetum.s, and 

 other means of dispersion possessed by seaweeds, and other low 

 organised plants. Among the higher plants, the seeds are in 

 many cases transported by the wind. .Sometimes, indeed, the 

 whole plant is thus blown about, as in the case of the celebrated 

 rose of Jericho, an animal inhabiting the sandy plains of Palestine, 

 Syria, and Arabia, which when dry curls itself up into a ball, 

 and is thus blown over the siu'face of the ground till it comes to a 

 damp place when it uncurls, the pods open and shed their seed. 



Many seeds are provided with a wing which catches the wind 

 and thus aids in dispersion. Such seeds occur especially on 

 trees, such as the pine, fir, ash, maple, sycamore, hornbeam, 

 and many exotic species. In these cases the seeds are lai^e, 

 but many herbs have small seeds provided with foliaceous 

 expansions serving the same purpose. These are sometimes 

 so thin as to be transparent ; and in Thysanocarpus elegans, 

 the membrane is even perforated by a series of holes. In other 

 cases the seeds are provided with hairs which catch the wind, 

 sometimes forming exquisite fairy parachutes. Such for instance 

 are the dandelion, &c., but it is curious that very different parts 

 of the plant are modified into these hairs : thus in the dandelion 

 and valerian it is the calyx, in the buUrush the perianth, in the 

 willow-herb the crown of the seed, in the cotton-grass the base. 

 In the true cotton the whole seed is covered with hairs. 



Thus then, although the result is the same, the mode of 

 arriving at it is very different. He then proceeded to the 

 cases in which the dispersion of seeds is effected by the agency of 

 animals. In many cases the seed is surrounded by a sweet 

 fleshy pulp which is eaten, while the true seeds being sur- 

 rounded by a tough shell, remain undigested. Such fruits 

 are generally brightly coloured such as the strawberry, peach, 

 apple, ciu-rant, &c., the colours like those of the flowers 

 serving to attract animals. In other cases the action of animals 

 is involuntary. These may be divided into two classes : those 

 in which the seeds adhere to animals by hooks, and those 'in 

 which this is effected by sticky glands. Various cases of both 

 were cited, and specimens shown, especially the South African 

 Harpagophyton, a plant whose seeds are provided with terrible 

 hooks more than an inch long. These seeds are said sometimes 

 even to destroy lions, they roll about on the sandy plain, and if 

 one attaches itself to the skin, the wretched animal tries to tear 

 it off, and getting it into its mouth, perishes miserably. Sticky 

 seeds are also thus transported. 



SECTION E 



GEOGRAPHY 



Opening Address by Clements R. Markham, C.B., 

 F.R.S., F.L.S., Sec. R.G.S., F.S.A., President of the 



Section. 



I propose to open the proceedings of this Section by 

 attempting to place in a clear light the objects and aims of 

 geographers, and the position which their science holds relatively 

 with reference to the other sciences, and positively as a distinct 

 body of knowledge with defined limits. 



Geography is a knowledge of the earth as it is, and of the 

 changes which have taken place on its surface during historical 

 times. These changes explain to us the laws according to which 

 similar changes are now taking place around us. The subject 

 may be considered from various points of view ; but my present 

 endeavour will be to introduce to you, through the remarks I 

 propose to make, the papers that will come before you to-day 

 and at our subsequent meetings. I shall try to do this by explain- 

 ing the practical uses of geographical knowledge, and its import- 

 ance to us in almost every occupation in which we may be 

 engaged. 



Our first work as geographers is to measure all parts of earth 

 and sea, to ascertain the relative positions of all places upon the 



J 



