Oct. 20, 1887] 



NATURE 



5S1 



First position. 



Second position. 



the field of coffee presents a sheet of white. These flowers are 

 frequented by immense numbers of bees, of two kinds, one about 

 three-quarters of an inch long and black,the other smaller and with 

 white bands round its abdomen. The stigmas now are covered 

 with pollen, and the anthers bursting, and the larger of these bees 

 may be seen buzzing from flower to flower sweeping up the 

 grains of pollen between its front legs, and rolling them into 

 balls. Long before evening all the anthers are exhausted of 

 pollen, and the insects have departed. Besides bees some 

 butterflies visit coffee, such as HypoUmnas bolina, Papilio 

 Polyinnestis, and two or three DauaidiC. 



The coffee plant by being proterogynous is intended by Nature 

 to be cross-fertilized, but owing to all the plants in one clearing 

 being usually grown from seed of a single estate, there must be 

 a great deal of interbreeding, more especially as all the coffee 

 of Ceylon and most of South India is supposed to be descended 

 from a single plant introduced into Batavia about two centuries 

 ago. This may have something to do with the . manifest 

 deterioration in stamina of the younger coffee. 



While on this subject I may mention the curious alteration in 

 the position of the organs of Clerodendron inforlunatnin when 

 flowering. This plant is proterandrous : at first the style hangs 



I ^ 



^^e stamens drop, while the style rises, and the stigma becomes 

 receptive. The chief carriers of pollen in this plant are small 

 ants. T. F. Bourdillon. 



Quilon, S. Travancore, India, September 13. 



Pearls oi Jasminutii Sambac. 



Dr. Rieuel tells us in Nature of September 15 (p. 461), 

 that he possesses in his collection two melati pearls of Jas- 

 minum Sambac. I beg to say that, as in the case of tabasheer 

 (see Nature, vol. xxxvi. p. 30), and in that of cocoa-nut 

 pearls {ibid. p. 158), Kumphius, in the almost inexhaustible 

 treasure of his " Herbarium Amboinense," has already mentioned 

 the pearls found also in the flowers oi Jasviiniim Sambac. He 

 gives in his fifth volume, in the 30th table, a good picture of 

 that plant, and says in the description that a "dendrites" found 

 in its flower in 1672 was sent to him two years after. It had 

 the shape of a bud of the same vegetable, and was white- 

 coloured and hard like silica or alabaster ; moreover, it must have 

 been without doubt a carbonate of calcium or some other 

 alkaline earth, for Rumphius remarks that when the pearl was 

 imprudently moistened with citric acid part of it was consumed 

 by the acid. He also tells us that the common name given to 

 all stone-concretions in fruits, wood, and animals by the Malayan 

 people is "mestica," which corresponds well with Dr. Riedel's 

 name of "mustica." [" In Celebe, ac prassertim in Macassara 

 in cunctis saspe fructibus dendrites quaedam reperiuntur, ubi 

 inter alia in hoc quoque frutice (Jasminum Sambac) talis detecta 

 fuit, qua; loco floris inventa full anno 1672 in horto quodam 

 Germani ibi habitantis, qua^que mihi biennium post transmissa 

 fuit. Formam habebat capituli, seu instar veri floris Bonga 

 Manoor, nondum aperti, eratque alba et dura instar silicis seu 

 alabastri ; inventa autem fuit in tubo veri floris atque petiolum 

 habebat ex ligno et lapide sensim compositum ; quique banc 

 invenerat, imprudenter in mcnsa deposuerat, limonum succo 

 commaculata, qui subito eius portionem consumserat."] 



Frankfurt a. Oder. E. HuTii. 



Action of River Ice. 



In the year 1854 the Yellow River burst through its left em- 

 bankment near Kaifungfu, and took a new course to the sea 

 through the province of Shantung, occupying in its lower course 

 the bed of the Tatsing-ho, which it scoured out and widened. 

 Prior to the change the Tatsing-ho had been crossed at Tsiho- 



hien, about seventeen miles above Tsinan-fu, the provincial 

 capital, by a stone bridge, seven arches of which remained 

 standing in 1868 when Mr. Ney Elias visited the river (see 

 Journal Roy. Geog. Soc. vol. xl. p. 6). Owing to the increased 

 width of the channel, this bridge only reached about three- 

 quarters of the distance across the river, and formed a serious 

 impediment to the navigation. 



Crossing the river myself at this site in April last, I made 

 inquiries regarding the old bridge, but, as customary in China, 

 could elicit nothing definite ; the bridge had gone, and no visible 

 obstruction existed in the channel. 



When I arrived in Tientsin in July, the Yellow River was a 

 frequent subject of conversation, and an old friend and well- 

 known resident, Mr. J. G. Dunn, gave me the following account 

 of a curious phenomenon witnessed by him when crossing the 

 river in January 1883, on his way overland to vShanghai. The 

 winter was a severe one, and the ice on the Yellow River at 

 this spot was about three feet in thickness. Most of the 

 ordinary traffic of the district was carried across the ice in carts 

 and wheelbarrows ; a space was, however, kept open for the 

 ferry, by which usually the entire traffic of the high-road from 

 the capital crosses the river, the ice being broken up every 

 morning so as to leave a clear passage. Mr. Dunn preferred 

 crossing the river by the ferry, as seeming to him more convenient 

 and safer. From the boat he witnessed the extraordinary sight 

 of a stone bridge floating on the upper surface of the ice ; the 

 piers had apparently been lifted bodily up, some of the arches 

 were standing, still supported at one end by an .abutment, but 

 some had fallen, and were resting as they fell in order on the 

 surface of the ice. The bridge had apparently floated some 

 distance down ; Mr. Dunn thought, from the confused answers 

 of the people, a considerable distance, but from a comparison of 

 the site it could scarcely have been more than a hundred yards 

 or so. Strong westerly winds had been blowing for some time, 

 and probably had, combined with other causes, induced a 

 slight rise in the level of the water sufficient to break the con- 

 nexion of the ice-sheet with the banks ; the space kept open for 

 the ferry had enabled it to move downwards by degrees under 

 the influence of wind and current, and as the piers of bridges in 

 China are usually built without cement they offered little 

 obstruction to the movement. 



From my own experience of the people in the district I can 

 understand Mr. Dunn's mistake as to the distance the bridge was 

 carried, and there can be no doubt that the bridge seen was the 

 original one described by Mr. Elias, 



The fact of a bridge lifted bodily off its piers by the floating 

 power of river ice is probably unique, but in any case is 

 sufficiently interesting to be worthy of record. I may add that 

 the latitude of Tsiho is approximately 36° 40' N. , and the width 

 of the river about 2coo feet. Thos. W. KiNGSMILL. 



Shanghai, August 26. 



Unusual Rainbow. 



A RAINBOW after sunset is probably a somewhat unusual 

 occurrence, but on the evening of September 1 1 I witnessed a 

 very beautiful one from the band-stand in the Alfred Park, which 

 is about the highest ground in Allahabad, Just before sunset 

 the sky was more or less covered with high cirro-stratus, and 

 promised one of the very highly-coloured sunsets common in 

 the rainy season, while at the same time a slight storm, heralded 

 by distant thunder, was coming up from the east. After spend- 

 ing a few minutes in the Public Library near the band-stand, I 

 came out, and found the sun had set behind a bank of what 

 Abercromby calls " rocky cumulus," or some other lumpy form 

 of cloud, and was sending long shafts of alternate light and 

 shadow across the southern half of the sky, while towards the 

 north and overhead the clouds were lighted up with the most 

 gorgeous colours. On turning to the east to see whether the 

 flutings of the cloud-shadows appeared to meet in that quarter, 

 as they usually do, I saw on the approaching shower, which was 

 towards east-south-east, a beautiful double rainbow, both arcs 

 being some 20° long, but stopping short of the horizon by 

 ii°or 2°, to which height the e.arth-shadow already extended. 

 Both bows seemed to the eye to be somewhat narrower than 

 usual, and between and beyond them the fluted cloud-shadows 

 appeared, by the illusion of perspective, to converge towards the 

 anti-solar point. The bow must therefore have been produced 

 by the light from a portion only of the sun's disk, shining through 

 a hollow on the top of the western bank of cloud, and doubtless 



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