January 5, 1893] 



NA TURE 



^p 



«or its thickness, so that the old trees look top-heavy. The date 

 palm flourishes in Honolulu, where it is quite dry, but does not 

 do so well in the wetter parts of the islands. 



On studying the other irees, one is struck at once by the great 

 preponderance of Leguminosse, especially Csesalpinese and 

 Mimoseae. All about the town, and growing very rapidly, is 

 the algaroba {Pi-osopis jiilijlora), a very graceful tree of rapid 

 growth, with fine bipinnate leaves and sweetish yellow pods, 

 which animals are very fond of, and which are used extensively 

 for folder. Add to this that the tree now forms the principal 

 supply of fuel for Honolulu and we can realize its full value. 

 Other leguminous trees that are planted are the monkey-pod 

 (Pithecolohium samang), tamarind, various species of Bauhinia 

 and Cathaitocarpus. One species of the latter with great 

 drooping bunches of golden yellow flowers and enormous 

 cylindrical pods three or four feet long, rivals the Poinciana 

 when in full flower. 



Mingled with these are a great number of shrubs and trees 

 with showy flowers or leaves, most of them more or less familiar 

 to the stranger, either from pictures or from green-bouse speci- 

 mens. Several species of Musa are grown, and when sheltered 

 from the wind are most beautiful ; but ordinarily the leaves are 

 torn into rags by the wind. The tall and graceful M. sapientium 

 has been largely supplanted by the much less beatiful Chinese 

 banana, M. Cavendishii, which is short and stumpy in growth, 

 but enormously prolific. The related traveller's tree {Ravenala 

 Madagascar ieji sis), is a common and striking feature of many 

 Hawaiian gardens. Of the many showy fl )wering shrubs, the 

 beautiful Hibiscus Rosa-Sinensis is one of the commonest, and 

 is used extensively for hedges. One of the most striking hedges 

 in the city, however, is the famous one at Puna Hou college, 

 which is 500 feet long and composed of night-blooming cereus. 

 I was not fortunate enough to see this when it was in full flower, 

 but I saw a photograph of it when it was estimated that there 

 were about 8000 flowers at one time. 



Of the fruit trees ordinarily grown, the following may be men- 

 tioned. The mango is a very handsome tree with dense dark 

 green foliage and masses of yellow and reddish fruit on long 

 hanging stalks. The bread-fruit tree is common, both cultivated 

 and wild, and is a very beautiful tree of moderate size, with 

 leaves looking like immense fig-leaves, and the fruit like a large 

 osage orange. I saw no ripe fruit, and so had not an oppor- 

 tunity of testing its quality. Guavas of different varieties are 

 extremely common, both wild and cultivated, and the various 

 fruits of the whole citrus tribe grow well. The few specimens 

 of temperate fruits were, for the most part, much inferior to 

 those of the United States. Of the fruits that did not strike my 

 fancy, at least at first, was the alligator pear {Persea gratissima), 

 a big green or purple pear-shaped fruit with an immense single 

 seed. The pulp is somewhat waxy in consistence and very oily. 

 It is eaten as a salad, and very much relished by the islanders, 

 but the taste is acquired. The curious papaya {Caric a papaya) 

 is another fruit which did not appeal to my palate. Its big 

 orange fruit, not unlike a melon in appearance when cut open, 

 has a peculiar "squashy'" flavour that suggested it having been 

 kept a day too long. 



Many showy climbers are planted, some of which, like 

 Stephanotis, Thunbergia and Allamanda are superb ; but there 

 is one that is particularly obnoxious in colour, Bougainvillea, 

 whose magenta floral-bracts are an offence to the eye, forming a 

 cataract of raw colour. It looks, as some one observed, as if it 

 had just come from a chemical bath. 



As soon as one gets fairly away from the city, it is at once 

 seen that all the luxuriant vej^etation is strange. Along the 

 seashore is a plain gradually ri<;ing into low hills, both almost 

 destitute of trees, except here and there a few cocoa palms along 

 the shore. Of the strictly littoral plants among the most con- 

 spicuous is the curious Ipomcea pes-caprce, with deeply two-cleft 

 leaves and purplish pink flowers. In the fertile lowlands near 

 the sea are the principal cane and rice fields, which with taro 

 are the staple crops. The rice is cultivated entirely by Chinese, 

 near Honolulu ; but on the sugar plantations the Japanese are 

 largely employed. To see a Chinese laboriously transplanting 

 little handfuls of rice into straight rows, or ploughing in the mud 

 anf* water with a primitive plough drawn by a queer Chinese 

 buffalo are sights very f treign to an American eye. Sugar cane 

 is eminently productive in the islands, and, hitherto, has proved 

 the main source of revenue ; but now the Hawaiians are bewail- 

 ing the depression caused by the free admission of sugar from 

 other countiies into the United States ; as, hitherto, their pro- 



NO. 1 2 10. VOL. 47I 



duct has enjoyed practically a monopoly of the American 

 market, having been admitted by treaty free of duty. 



I made several trips up the valleys back of the city, but owing 

 to the almost constant rain in many of them, these were not 

 always agreeable. However, one is richly repaid by the 

 luxuriance and variety of the vegetation. For a mile or two we 

 pass between grass-covered hills, or hills overgrown in places 

 .with thelantana, which, introduced as an ornamental plant, has 

 become a great pest. This plant covers some of the hills with 

 an absolutely impassable thicket, and spreads very rapidly, so 

 that it is a serious problem what is to be done with it. Of 

 the common roadside plants, an orange and yellow milk- 

 weed and the showy white Argemone Mexicana were the 

 most conspicuous. As one proceeds farther, where more 

 moisture prevails, the variety becomes larger. Thickets of 

 Canna and a Clerodendron with double rosy-white flowers, are 

 common, and the curious screw-pine {Panianus odoratissimus) 

 is occasionally seen. This latter is a very characteristic plant, 

 but is much more abuudant in some of the other islands. 

 In this region some very showy species of Ipomoea are very 

 common, among them the well-known moon-flower, /. bona-nox. 



With the incease in moisture, as might be expected, the 

 mosses and ferns increase in number and beauty. There are 

 many of them of types quite different from those of the United 

 States. One of the commonest ferns of the lower elevation io 

 Microlepia tenuifolia, a very graceful fern with finely divided 

 leaves and terminal sori. Species of Vittaria, with very long 

 undivided leaves, are also common here. 



As we ascend one of the commonest ferns is Sadleria 

 cyatheoides, a very large fern, often more or less arborescent. 

 Ascending still higher the number and variety of ferns increases 

 rapidly, and many beautiful and interesting ferns and mosses 

 and liverworts become common. 



At about one thousand feet elevation we begin to meet 

 with species of Cibotium, to which genus belong the largest of 

 the tree ferns of the islands. Here, also, I met for the first time 

 with the smallest of all the ferns I have ever seen, Trichomanes 

 pusillum. This dainty little fern, one of the Hymenophyll icese, 

 forms dense mats on rocks and tree-trunks, looking like a deli- 

 cate moss. The full-grown frond is fan shaped, and, with its 

 stalk, is not more than half an inch high. These tiny leaves, 

 nevertheless, in many cases bore sporangia. 



SOCIETIES AND ACADEMIES. 

 London. 



Royal Society, December 8. — " Preliminary Account of 

 the Nephridia and Body Cavity of the Larva of Palcemonetes 

 varians." By Edgar J. Allen, B.Sc, University College, 

 London. Communicated by Prof. W. F. R. Weldon, F.R.S. 



The Green Gland, m a larva of Pa'ctmonetes which is a few 

 days old, consists of an end-sac, which communicates by means 

 of a U-shaped tube with a very short ureter, opening at the base 

 of the second antenna. At the time of hatching, the gland 

 consistsof a solid mass of cells, without a lumen. In later stages 

 the tube of the gland enlarges to form the bladder. The en- 

 larged bladders of the two sides subsequently meet and fuse in 

 the middle dorsal line, forming the nephroperitoneal sac described 

 by Weldon and Marchal. 



The Shell Gland is found in late embryos and young larvae 

 of Palcemonetes. It consists of a short renal tube, with a con- 

 siderable lumen, which communicates internally with an end- 

 sac, and opens externally at the base of the second maxilla. 



Sections through the anterior region of the thorax of Pala- 

 tnonetes show that the body cavity may be divided into four 

 regions : a dorsal sac, surrounded by a definite epithelium, in 

 which the cephalic aorta lies, but which does not itself contain 

 blood; 3. central cavity, coMaXningWweT, intestine, and nerve- 

 cord ; two lateral cavities, containing the proximal ends of the 

 shell glands ; and fourthly, the cavities of the limbs, which con- 

 tain the distal ends of the same organs. 



In late embryos of PalcBtnonetes solid masses of cells lie upon 

 either side of the cephalic aorta. The dorsal sac is formed by 

 the hollowing out of these masses of cells. Two lateral cavities 

 are thus formed, which are separated by the aorta. The proto- 

 plasm of the cells lining these cavities, which is at first gathered 

 into masses around the nuclei, then spreads out into a thin 

 sheet, drawing away from the lower portion of the aorta, and. 

 causing the two lateral cavities to unite ventrally, and so form a. 

 single sac. 



