584 



NATURE 



[April 2^^ 1879 



of the eighty-first degree of north latitude, on or near the 

 shore of Lady Franklin Bay, for the purpose of scientific 

 observation and exploration, and to develop or discover 

 new whaling grounds ; such officers as may be necessary 

 to be detailed to take part in the same, and with permis- 

 sion to use any public vessel or vessels in connection 

 therewith. This is essentially Capt. Howgate's plan, and 

 probably introduced by his request. 



The last number of the Indian Antiquary contains a 

 note by Major J. S. F. Mackenzie on some curious 

 customs current among the Komti caste in regard to 

 marriage, &c. "A Folklore Parallel," by Prof. C. H. 

 Tavney, of Calcutta, is also worthy of notice. 



Mgr. Lavigerie, Archbishop of Algiers, communi- 

 cates to Les Missions CatJioliques intelligence respecting 

 the portion of the French missionary expedition in East 

 Africa, which, under the leadership of Pfere Livinhac, was 

 gradually making its way towards Lake Victoria. At the 

 date of the letter (December) the five Europeans were all 

 in good health, and were then in Mirambo's country, on 

 the way to Uganda. P^re Livinhac writes that they had 

 been three months in Unyanyembe, and that they were 

 then twenty or thirty days' march from the lake. In the 

 same number of Les Missions CatJioliques Mgr. Ridel 

 continues the account of his recent captivity in Corea, in 

 which he gives a terrible picture of the prisons of the 

 country. 



A TELEGRAM from Malmo states that the s.teamer 

 Nordenskjold, built for M. Sibiriakoff, to go to the as- 

 sistance of Prof. Nordenskjold' s expedition, was launched 

 on the 17th inst. 



A VERY interesting narrative of travel has just been 

 commenced in the Tour du Monde, entitled " Voyage en 

 Nouvelle Guinde," by M. Achille Raffray. The first 

 instalment deals with the Moluccas, which M. Raffray 

 visited en route, but in the second he commences his 

 work in New Guinea. The illustrations are unusually 

 good. 



BIOLOGICAL NOTES 



The Early Types of Insects.— Samuel H. Scudder 

 has published a memoir on the early types of insects 

 {Memoirs of the Boston Society of Natural History, vol. 

 iii. Part i. No. 11, March, 1879). He concludes that the 

 hexapods, arachnids, and myriapods appeared together in 

 the carboniferous strata. That the hexapod insects may 

 be divided into a higher group (Metabola), and a lower 

 group (Heterometabola), that the latter are Devonian 

 and carboniferous, the former just appearing in the 

 Jurassic period. The Devonian forms were in the early 

 stages of their life, undoubtedly aquatic. Nearly all the 

 palaeozoic orthoptera belong to the lower Saltatorial 

 families. It would seem that the earlier types were of 

 inferior organisation, and that the general type of wing 

 structure in insects has remained unaltered from the 

 earliest times. 



Halosph^ra, a New Genus of Unicellular 

 AlGjE. — Under this name Dr. F. Schmitz describes, in 

 the first "Heft" of the first volume of the Mittheilungen 

 aus der zoologischen Station su Neapel, an organism 

 which is found abundantly between the middle of January 

 and the middle of April, floating on the surface of the 

 water in the Bay of Naples. Hitherto kno%vn to col- 

 lectors simply as punti verdi, Dr. Schmitz gives it the 

 name Halosphcera viridis. It presents to the naked eye 

 the appearance of minute just visible pale green globules, 

 the largest having a diameter of from 0-5 to o'6 min., but 

 with no independent power of motion like that of Volvox. 

 Each globule consists of a tolerably thick perfectly smooth 

 and colourless cell- wall, coated on the inside with a thin 

 layer of pale green protoplasm, which incloses a single 

 very large central vacuole filled with a colourless cell-sap. 



The green colour of the protoplasm is due to its being 

 interspersed with a small number of minute grains of 

 chlorophyll ; and there is also, at an early stage, a single 

 globular nucleus with a somewhat darker nucleolus. As 

 the cell increases some^vhat slowly in size, the process of 

 cell-division commences. The single nucleus divides into 

 two nuclei, which gradually separate from one another ; 

 and this process is repeated .time after time, until a very 

 large number of nuclei, which the author reckons to 

 average from 200 to 300, come to be tolerably regularly 

 distributed through the parietal protoplasm of the mother- 

 cell, which has by this time attained its full size. The 

 layer of protoplasm then breaks up into a number of 

 primordial daughter-cells, each surrounding one of the 

 nuclei, and having the form of a hemispherical ball, the 

 flat surface of which is in contact with the cell-wall of the 

 mother-cell. They are of a uniform bright green colour, 

 without apparently containing any distinct grains of chloro- 

 phyll. The external cellrwall of the mother-cell has now 

 become differentiated into two distinct layers, the outgr 

 one of which bursts into two nearly equal halves, and 

 becomes completely detached from the inner one, which 

 now itself consists distinctly of two layers. The hemi- .■ 

 spherical green daughter-cells then become transformed 

 into zoospores of a very peculiar shape. They begin gradu- 

 ally to detach themselves from the^outer cell-wall, and to 

 take up positions in the interior of the cell. In most 

 cases each of them contracts in the centre into somewhat 

 the shape of an hour-glass, but pointed at the two ends, 

 ultimately dividing in the middle into two zoospores of 

 conical shape, with a nearly, flat base, but toothed at the 

 edges, and a pointed apex. To a colourless protuberance- 

 in the centre of the nearly flat base are attached two very 

 long vibratile cilia. Sometimes only a single zoospore is 

 formed from each of the primordial cells, and occasion- 

 ally more than two. The remaining cell-wall of the ! 

 mother-cell has, in the meantime, been gradually swell- 

 ing up and deliquescing, and has now become completely 

 converted into nrucilage, so that the zoospores escape 

 free into the surrounding water. After moving about for 

 'some time with a rather slow swarming motion, they 

 fall to the bottom ; but their further development has not 

 been followed up. Until its complete life-history is 

 known, it is impossible to assign a systematic position 

 to Halosphcera. It may possibly come near Eremo- 

 spha:ra, a genus of Conjugatae ; its resemblance to Volvox ■ 

 is clearly only superficial. 



A New Alga.—Iu the first Heft of the ist vol. of the 

 Mittheilungen aus der zool. Station zu Neapel, Dr. Falken- 

 berg describes a new genus of Phseosporeae under the name 

 Discosporangium, with the following characters : — Thallus, 

 an irregularly branched filament, consisting of a single 

 row of cells, and growing by an apical cell. Reproduc- 

 tion by zoospores, which are formed singly in the com- 

 partments of multilocular zoosporangia. The zoosporan- 

 gia are placed singly near the middle of the cells of the 

 thallus, forming a square unilamellar plate, the com- 

 partments of which open separately when ripe on the 

 upper side of the sporangium. 



In the second Heft of the same publication Dr. Falken- 

 berg gives a complete list of the marine Algse of the Bay 

 of Naples. 



Marine Flowering Plants.— Dr. I. B. Balfour has 

 just published {Transactions Bot. Soc. Edinburgh J 

 Session 1877-78) a most valuable and interesting memoir 

 on two species of the genus Halophila, found verj 

 abundantly in widely extended patches on the reefs 

 surrounding the island of Rodriguez. The»island was 

 visited in 1874 by Dr. I. Balfour as naturalist accompany-^ 

 ing the "Transit of Venus" expedition. Of the twC" 

 species one, H. ovalis, grows on spots which are jusl 

 uncovered at low tides. The other, H. stipulacea, grows 

 in places where it is always submerged. Specimens 



