May 4, 1SS3.] 



SCIENCE. 



369 



U/rica.) 



Abbe Gruyot on eastern Africa. — This enter- 

 prising missionary leader gives a summary of tlie 

 difficulties encountered in entering Africa from Zan- 

 ziljar in )iis several ■expeditions since 1879. His party 

 included at times as many as six liuudred persons, 

 among whom brawls were very frequent, and ileser- 

 tion and robbery were prevented only by the strictest 

 watch. In passing the numerous Ugogo villages, 

 there was always delay and much i^alaver concerning 

 the imposts collected of travelling parties. The fever 

 presented the greatest danger. Sixteen of his thirty- 

 live missionaries died of it in three years, and four 

 more were killed by the negroes. Bad rejiorts are 

 spread by the Arabs about the Europeans, who are 

 represented as woman-stealers and cannibals. The 

 abbe bought and brought back witli him four native 

 children, who are now baptized and learning Latin, 

 as preparation for the study of medicine; for as doc- 

 tors they can exert the greatest influence. Guyot 

 was considered a great magician, because he cured a 

 native sorcerer who was unable to cure himself. It 

 was hoped that the Louaha, flowing from the coun- 

 try east of the lal<es to the ocean, might prove an 

 easy means of communication with the interior; but 

 it was found unnavigable. Large game was common, 

 and gave plenty of food for cheap living for the cara- 

 vans. The natives call '.c//j. (jlW when hunting the 

 hippopotamus; and, if within hearing, it rises from 

 the shallow, muddy banks of the river, and comes 

 towards them. This was tried many times, and 

 always proved successful. The friendly native tribes 

 are good-hearted; but they must be allowed their 

 own peculiar ways, such as shouting and dancing all 

 night to do honor to the white travellers to whom 

 they had presented food. The abbi5 hopes soon to go 

 to western Africa, and ascend the Kongo. ^(C'omyjtes 

 rendus soc. gimjr. Par in, 1883, 44.) w. Ji. D. [776 



Climate of the upper Senegal. — JI. Colin, phy- 

 sician of Commandant Derrien's topographic party to 

 the upper Senegal in ISSO-Sl, divides the year there 

 into a dry aiul a wet season, and two transition 

 periods, — the dry season, from Nov. 15 or Dec. 1 to 

 March 1.5, "with nights and early morning hours cool, 

 and days supportable; transition, from March 15 to 

 May 15, still dry and healthy, but very warm and 

 imcomfortable for Europeans ; the rainy season, from 

 May 15 to Oct. 15, cooler and often cloudy, without 

 evaporation from the marshes, and hence still healthy ; 

 the s,econd transition, from Oct. 15 to Nov. 15 or Dec. 

 1, still somewhat rainy, but with subsidence of rivers 

 and drying of low plains, excessively unhealthy. — 

 {Comptes rendus soc. geoyr. Paris, 1883, 86.) w. M. D. 



[777 



Country of the upper Niger. — Commandant 

 Gallienl's second paper gives many details on the hy- 

 drography and population of this region, and a few 

 notes on its geology. The rocks are chiefly horizon- 

 tal sandstones, showing barren plateaus, separated by 

 fertile valleys, in which the streams are subject to 

 rapid and regular floods, rising in June, and falling 

 in December. The Niger is considered in three parts. 

 The upper stream begins at the rocks of Sotuba, ten 

 kilometres below Bammako, and extends through 

 the broken country to its head waters, but even 

 here probably in part navigable for small steamboats. 

 The middle course includes the least-known part of 

 the river from the rocks of .Sotuba to the falls of 

 Busa. Here the stream flows in numerous channels 

 through a flat country, which it enriches. An active 

 river-trade in slaves, cattle, gold, etc., is carried on 

 between large "villages on its banks. This division 

 is more navigable than the first. The lower course 



extends from the falls of Busa to the sea, and has 

 often been ascended a consideral)le distance by trad- 

 ing-vessels. The total length is over 2,000 miles. 

 Several of the towns described have well-constructed 

 fortification walls, which are illustrated by plans and 

 figures. On the assault of the village Gubanko in 

 18S1, a hundred can-non-shot were needed to make a 

 breach two or three metres wide. — (Bull. soc. (jeoqr. 

 Pari.5, 1882, 616.) "(V. M. D. [778 



BOTANY. 



Ohio fungi. — In a paper on the Mj'cologic flora 

 of the Miauii valley, Mr. A. P. Morgan has given 

 descriptions of eighty species of Agaricus belonging to 

 the division Leucospori, found in south-western Ohio. 

 The ijaper is accompanied by four colored plates, iu 

 which are figured six new .species of Agaricus. — 

 {Journ. Cine. soc. nat. hist., vi.) w. G. F. [779 



Diseases of trees. — The third part of the Unter- 

 suchungen aus dem forstbotanischen institut of Mu- 

 nich contains several articles on the diseases of woody 

 plants caused by fungi. Dr. H. Mayr has a paper on 

 the disease -of maples, linden, and horse-chestnut, 

 caused by Nectria cinnabarina. Prof. Robert Hartig 

 describes a new species, Rhizomorpha (Dematophora) 

 necatrix, which he considers to be the cause of the 

 root-rot in grape-vines. The Rhizomorpha produces 

 conidia,which are figured by Hartig; but he was unable 

 to find ascospores of any kind. While recognizing 

 that the root-rot is caused by a species of Rhizomor- 

 pha, be differs from Millardet and Frank, wlio con- 

 sider that the Rhizomorpha is the same as R. fragilis, 

 which develops into Agaricus melleus; and, on" ihe 

 other hand, he differs from Prillieux, Thuemen, and 

 others, who attribute the rot to a growth of Roesleria 

 hypogaea, "which Hartig considers to be merely a sa- 

 prophyte which occasionally develops on the diseased 

 roots. Hartig calls attention to the fact that in Ger- 

 many the white pine of the United States (Pinus 

 strobus) is especially susceptible to fungous diseases, 

 and mentions several destructive fungi whicli are 

 prone to attack it: among others, he cites Pei'ider- 

 mium pint. In this respect the experience of Ger- 

 man mycologists does nut agree with observations 

 made in this country, where tie white pine is appar- 

 ently less liable than some other species to attacks of 

 the Peridermium. — w. G. F. (780 



Insects and the spermogonia of TJredineae. — 

 For several years Rsithay has been studying the rela- 

 tions between the rust-fungi and certain insects which 

 visit their spermogonia to feed upon the speimatia 

 and a sugary excretion whicli is found with them. 

 The fragrance of the spermogonia of a number of 

 species — e.g., Puccinia suaveolens of the Canada 

 thistle — has been noticed by everybody "who has 

 studied these fungi; and the brightly colored spots in 

 which they occur is equally well known. What bene- 

 fit the fungi derive from the visits of ants and other 

 insects is still to be shown, and will probably remain 

 a mystery until tlie true function of spermatia is 

 understood; but there is some reason for believing 

 that the color, fragrance, and sweet secretion of their 

 spermogonia are designed, like the similar peculiari- 

 ties of many pheuogamic flowers, expressly to at- 

 tract these visitors. — { Denkschrift. wien. akad,, xlvi.) 

 w. T. [781 



Notes on Echlnocactus. — Mr. Thomas Meehan 

 announced the discovery of sensitive stamens iu 

 Echlnocactus Whipplei. The motion of the stamens, 

 when touched, was not instantaneous, several seconds 



