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Summary The results of two series of measurements at 53° magn. Lat. N and 18° S. up to 5000 m of the ionisation in a vessel (4 L. 45 atm. argon) in a shield of 8 cm Fe, closed and open at the top are given. It was found that the ionisation was much higher at 53° lat. The radiation at 18dS. has the same nature at every height in the equatorial region and the same as the radiation at 53° at. which penetrates the 8 cm Fe. A comparison is made with results by means of the instrument at different heights on the earth.[

Results of the fading characteristics of the radio waves reflected from the two different heights in the F-region of the ionosphere over Ahmedabad are described in this paper using the wave frequencies of 5·7 and 7·0 MHz. Fading rates and angular spread are found to be smaller for the reflections from the higher levels (at 7·0 MHz) compared to those for the reflections from the lower levels (at 7·0 MHz) which is attributed to the larger size of irregularities existing at higher levels of reflections. Magnitude of fading rate is found to be higher in summer compared to any other season. A linear relationship is observed between the fading rates of the reflected wave and horizontal drift speed of the irregularities. Variations in the daily sum of magnetic activity has no effect on the magnitude of the fading rate.

While engaged in working out for the Zoological Society the Mollusca of the Expeditions which I undertook in 1869 and 1870 in H.M.S. ‘Porcupine,’ I was much struck by the discovery, at great depths in the North Atlantic, of certain shells in a living state which had been previously known only as Subapennine and South-Italian fossils, and were considered extinct. To give some idea of the extent to which such changes of sea and land must have taken place within a geologically recent period, I subjoin an extract from my paper on some of the ‘Porcupine’ Mollusca, which was published in the ‘Proceedings’ of the Zoological Society for 1879, pages 586 and 587. With reference to Malletia excisa , I said, “It will be seen that the last species, as well as many other deep-water shells which have been noticed in the present paper, are Calabrian and Sicilian Tertiary fossils. Besides these species, others of the same kind, and which had been also considered extinct (viz. Leda or Tindaria solida , Seg., Nucula glabra , Ph., and Malletia dilatata , Ph.), occurred in the ‘Challenger’ Expedition. The communication between the North Atlantic and the Mediterranean must have been formerly very different from what it is now, when a barrier or ridge in comparatively shallow water exists outside the Straits of Gibraltar, between Capes Spartel and Trafalgar. It is improbable that deep-sea Mollusca, even in their embryonic state, could have migrated or been transported under such conditions from one sea to another. The south of

1. The rate of decline in transpiration of an excised leaf or twig from an oak (Quercus coccinea Muenchh.) or pine (Pinus strobus L.) in the first 6 minutes after severing was found to be quite variable, depending on the species and the time of day. Oak leaves showed especially rapid decline in the afternoon, with definite decreases within 1 minute of severing; on similar days pine leaves were less responsive to cutting from the tree, whether twigs or fascicles were used, and transpiration declined only slightly after severing in the subsequent 6 minutes. 2. Night rates for oak often showed a slight increase after severing and then a decline about 3 minutes after severing, but the pine leaf transpiration was quite steady at night for the same 6-minute period. 3. Diurnal trends for either oak or pine transpiration showed that cloudy and clear days had about the same effect on total rates. Likewise, occasional periods of cloudiness during the day had no apparent effect in depressing the rate in either oak o...

It is expected that the evaporation will increase as one goes upward from the ground, but the amount varies considerably for different places and different conditions. It was partly with the view of ascertaining the values of such increases in the region about Douglas Lake, the location of the Biological Station of the University of Michigan, that the different pieces of work here reported upon were undertaken. The fact that evaporation increases with increase in height above the ground in marsh vegetation has already been brought out by Yapp 2 and confirmed by Dachnowski 3 and Sherff,4 in bog and marsh vegetation respectively. In the present investigation, not only marshes but also shrub and smalltree growths were utilized as experimental ground. The region is differently characterized climatically from that considered in either of the above-cited papers.5 METHODS

During part of the recent summer (1886), in addition to the ordinary temperature observations here, a set of readings were taken in a Stevenson screen, at a height of 112 inches above ground—that is, at about two and a half times the standard elevation of 48 inches. The high level screen was mounted at the top of a stand used to carry the thermometers in winter, and consisting of two stout upright posts or battens, with cross bars between them at every 2 feet or so; the screen is placed with the lower edge of the back resting on one bar, and is tied to the one above it or to the side posts. The screen used on this stand is smaller than the standard Stevenson screen, but it is constructed in exactly the same manner, with double louvred sides and the bottom open. It measures inside 10 inches broad by 6 inches deep and 15 inches high.

A study of the horizontal and vertical distribution of herbage in grass-dominant swards was made to assess the relative importance of different sources of wastage during grazing. A sward grazed by cattle under two contrasting managements was divided, for the purpose of herbage sampling, into two categories: ‘grazed’ herbage, on ground with no obvious dung contamination, and ‘dung patches’, which were of ungrazed or lightly grazed herbage resulting from the effects of faeces dropped at previous grazings. In each category, samples were cut at two successive heights to provide an estimate of the quantity of herbage in the upper region of the sward (over 2½ in. from ground level) and in the lower region (½-2½ in. from ground level).After grazing, some 35% of the original crop remained in ‘grazed’ areas, and some 20% in ‘dung patches’. In terms of vertical distribution, most of the residue (40% of the original crop) was in the lower region, from ½ to 2½ in. above ground level.Total production as live-weight gain was not significantly different, but the yield of conserved herbage was greater in treatment R (five rotations) than in treatment RR (nineteen rotations). Frequent grazing reduced herbage production, and this effect was not offset by any less intense defoliation of the frequently grazed sward. The average quantity of herbage residue was no higher in treatment RR than in treatment R, although the time of occupation per plot by the cattle in RR was only a quarter of that of the cattle in treatment R.

Two trap installations were operated during 1967 in Wilson County, North Carolina, to gather information on the flying heights of tobacco insects. In I installation, insect traps equipped with blacklight lamps were mounted at about 11-ft intervals to 99 ft above ground with the lowest trap 11 ft above ground; in a 2nd installation, traps were mounted at 5-ft intervals to 20 ft above ground with the lowest trap at ground level. Catches of tobacco hornworm Manduca sexta (Johannson), and tomato hornworm, M. quinquemaculata (Haworth), were notably larger in the ground-level trap than in higher traps, indicating that catches of trap installations using blacklight as an attractant are enhanced by operating a trap at ground level to capture moths going to the ground after being attracted to traps at higher levels. Height distribution in the traps is reported for the following 12 species: salt-marsh caterpillar, Estigmene acrea (Drury); black cutworm, Agrotis ipsilon (Hufnagel); cabbage looper, Trichoplusia ni (Hubner); armyworm, Pseudaletia unipulncta (Haworth); yellow-striped armyworm, Prodenia ornithogalli Guenee; corn carworm, Heliothis Zea (Boddie); tobacco hornworm, tomato hornwom, ground beetle, Harpalus sp.; carrion beetle, Silpha surinamensis F.; and May beetles Phyllophaga crenulata Froelich and P. lulctuosa Horn.