330 NATURAL SCIENCE. May. 



The Peopling of the World. 



The last of those valuable " Erganzungshefte " (number 107), 

 published at intervals by the proprietors of Petevmanns Mifteiluugen, is 

 devoted to the " Peopling of the World." Drs. Hermann Wagner 

 and Alexander Supan have to be thanked for the prodigious labour 

 involved in the compilation of this great census, the mass of figures 

 in which is simply appalling. The number consists of 130 pp., and 

 is crammed with information. The continents are taken in order, 

 and, whenever possible, the census of the actual town is given in 

 i8gi. Details of the previous census are also given in each case, so 

 that the reader may see at a glance the increase of population in a 

 certain number of years. Towards the end comes a list of the large 

 cities of the world and their inhabitants, and we extract the first six 

 as having special interest : — 



London (1891) 



Paris (1891) 



New York and Brooklyn (1890) 



Berlin (1890) 



Canton (1891) 



Vienna (1890) 



There are only 12 cities with ov 

 China rejoices in possessing four 



4,415,958 

 2,712,598 

 2,352,150 



1.763.543 

 1,600,000 

 1,364,548 



er a million inhabitants, of which 



Fresh-water Medus.^. 



Specimens of the fresh-water Medusa from Lake Tanganyika, the 

 same probably as that referred to by Bohm in 1883, and Wissmann 

 in 1887, have been received in good condition, and form the subject 

 of a paper by Mr. R. T. Giinther in the April number of the Annals 

 and Magazine of Nat, Hist. The individuals vary in size from i to 

 i*8c. across the bell, while the largest measured as much as 2*2c. 

 The umbrella is flattened ; the tentacles very numerous, varying in 

 length, and arranged to a sixth order with great regularity. Mr. 

 Giinther establishes a new genus, Limnocnida, for this interesting 

 animal, and preserves Bohm's name of tanganjicce for the species, 

 that author having recognised the form as new, although he was 

 unable to describe it in 1883 for want of the necessary literature. 

 The fresh-water Medusa which thrives in certain years in the tank at 

 the Botanic Gardens, Regent's Park, Limnocodium sozverbii, differs con- 

 siderably from this new form. 



The Plague of Voles. 



We have referred on several occasions to the subject of the 

 plague of Field- Voles in Scotland, and we shall, therefore, merely 

 chronicle the publication of the " Report of the Departmental Com- 

 mittee on Field- Voles (Scotland)," Pari. Paper — C. — 6943, 1893, price 



