December 28, 1883.] 



SCIENCE. 



831 



Sierra Leone. — According to recent consular re- 

 ports, the population of this colony comprises sixty 

 thousand five hundred souls, nearly all blacks, who 

 speak among them more than sixty different dialects. 

 Freetown, the capital, has a population of twenty- 

 two thousand, chiefly of the Aku, Ebo, Timen, Susu, 

 Maulang, Sherbru, and Krumen tribes. The Aku 

 and Ebo people are extremely keen traders: the three 

 following tribes furnish middlemen, who intervene 

 between the caravan merchants and the purchasers. 

 The last mentioned are freighters and boatmen, em- 

 ployed largely in loading and discharging vessels. 

 The trade amounts to about three million dollars 

 annually, less than h.alf of which are exports. The 

 soil is poor and not arable ; farming is hardly practi- 

 cable; and tlie real importance of the colony lies in 

 its geographical position, and easy communication 

 with the rich interior region. Taxes and customs- 

 duties are very high, and have injured trade by driv- 

 ing it elsewhere. The exports are kola, palm and 

 peanuts, palm-oil, gum-copal, rubber, ginger, and 

 hides. — (Bull. soc. Belg. gfogr., ii. 1S83. ) w. n. D. 



[561 



Portuguese Guinea. — Barros contriliutes a me- 

 moir on Portuguese Guinea, with notes on the r-us- 

 tonis and manners of the natives and on Iheir 

 language, especially of the M.andingo, Biafada, and 

 Balanta tribes, containing little absolutely new ex- 

 cept some songs. The article forms an interesting 

 summary of facts. — (Bol. soc. geog. Lisboa, no. 12, 

 1882.) TV. H. D. [562 



BOTANY. 

 Cryptogams. 



The oospores of the grape-mould. — Prillieux 

 states that he has receive<l from M. Frechou of X^rac 

 germinating oospores of Peronospora viticola. The 

 germinating oospores produce at once a mycelial tube 

 similar to that known in other species of Perono- 

 spora, in which the germination of the oospores has 

 been seen. This is an important step in our knowl- 

 edge of the grape-mildew, since, inasmuch as the 

 conidia produce zoospores, it had been supposed by 

 some that the oospores would also produce zoospores, 

 as is the case in the related genus Cystopus. — {Bull, 

 soc. hotan.) w. a. F. [563 



Sv7edish Algae. — Dr. C. Lagerheini describes a 

 number of species new to Sweden, including several 

 genera and species new to science. The species are 

 from fresli water, as well as marine, and arc illustrated 

 by a plate. Of the genera treated most in detail m.ay 

 be mentioned Merismopedium. — {OJ'vers. sveni'k. 

 akad.) w. o. r. [564 



Monograph of Ulvaceae. — The sixth part of 

 Agardh's Till algernes xi/atematik is devoted to the 

 Ulvaceae. The author includes here the genera 

 Bangia and Porphyra, as well as the green species 

 generally placed in this order. The subject is elabo- 

 rately prepared, and is illustrated by four colored 

 plates giving the microscopic structure. Ulva and 

 Enteroraorpha are kept distinct, and E. erecla is 

 credited to New York on the authority of J. Hooper. 



Monostroma pulchrum the writer suspects to be a 

 form of 31. lactuca, a boreal species of both hemi- 

 spheres. — (Acta univ. Lund., xix.) w. o. F. [565 



Phanerogams. 



Spines of Aurantiaceae. — Dr. Urban describes 

 and figures .specimens which .show that the spines 

 situated just above the leaf-axis of a number of mem- 

 bers of this family, and hitherto considered as meta- 

 morphosed axillary branches, .are in reality fonned by 

 the tr.ansformation of one or two of the lowest leaves 

 belonging to the primary axillary shoot. — (Ber. der 

 deutschen bot. geselhch., June 27.) w. T. [566 



Orchis mascula. — Mr. Malair believes that the 

 visits of bees to this species are for propolis, which is 

 yieliled by the iiapillae of the nectary. Flies also visit 

 the flowers, which are described at length, but not 

 very clearly nor accurately. — (Science gossip, March, 

 April.) w. T. [567 



Sterility of the Ficaria. — Mr. Neve notices that 

 in England the plant seldom seeds, although its 

 flowers appear well t'onned, and bees visit them. — 

 (.Science (/o.vti/), June. ) w. t. [568 



Pollination of -willovir. — Mr. Hamson states, that 

 while amentiferous plants, dependent entirely upon 

 the wind for fertilization, have pemlulous catkins, 

 " in the willow the catkins are upright aiul elastic. 

 The humble-bee is a heavy insect, and it almost in- 

 variably mounts to the summit of the calkin, which 

 is borne down by its weight. On the bee taking 

 fliglit, the catkin springs sxuldenly to its original po- 

 sition, aud thus shakes out the pollen in the male, 

 and further distributes that which may have lodged 

 in the scales of the female catkin." Bees were no- 

 ticed to confine their visits almost exclusively to the 

 stamin.ate plants. — ( Scienre i/os*!/), July. ) w. t. [569 



ZOOLOGY. 



Protozoa. 

 Division of the nucleus in protozoa. — It is 

 known that in many protozoa the number of nuclei 

 increases with the growth of the animal ; but whether 

 the additional nuclei arise by free new formation, or 

 by division of older nuclei, w.as uncertain, although 

 Zeller had shown that the multiplication In Opalina 

 was due to division. Gruber, iu a valuable article, 

 now shows that in Actinospaerium and Amcjeba divis- 

 ion of the nuclei occurs, having obtained examples 

 after very long search. In the former the young nu- 

 clei are small, and have a single large nucleolus with 

 a clear space around it. As the nucleus enlarges, the 

 clear margin disappears, and the nucleolus breaks up 

 into smaller granules (nucleoli). In one specimen 

 various stages of division were found. Their natural 

 succession is probably as follows : the nucleoli arrange 

 themselves in two parallel rows across the nucleus; 

 they then unite so as to form a homogeneous band 

 out of each row; the rest of the nuclear substance 

 accumulates between the two bands, which then 

 move asuiuler, and meanwhile threads appear run- 

 ning from band to band; a liiur of division (par- 

 tition-wall ?) appears between the bands. In Amoeba 

 proteus the nucleus contains a peripheral layer of 



