348 
INA TLL 
| FEBRUARY 7, 1907 
lake shore, the region which is the special haunt of the 
tsetse-fly in question, while at the lake ports, such as 
Entebbe and Jinja, every effort is being made to oust the 
fly by destroying the vegetation which harbours it, and 
Entebbe is already reported to be clear of fly. It is only 
to be hoped that the process of deforestation will be carried 
out with discretion as well as with zeal, and only those 
tracts denuded of forest which have been definitely proved 
to harbour the tsetse; a forest tree may be destroyed in 
half an hour which a hundred years will not replace. 
The experience of other diseases transmitted by biting 
insects, as yellow fever, indicates that the most 
efficient method of preventing the spread of the disease is 
to isolate the patients in such a way as to prevent them 
from infecting the insects which are the carriers. If it is 
possible to carry this out on so large a scale as the Pro- 
tectorate Government is trying to do it, we may hope to 
see in a few years the disease stamped out completely in 
the territory of Uganda. The Commissioner is to be con- 
gratulated on the promptness and energy with which he 
turning the conclusions of scientific investigation to 
practical use. 
such 
is 
AN interesting innovation in coal-mining practice is re- 
ported from the United States, where at a colliery at 
Shamokin, Pennsylvania, concrete has been substituted for 
mine timbering. A plant for the manufacture of these 
cement props is in course of erection at Trevorton. 
On January 28 coal was struck at Lord Dudley’s sink- 
ings at Baggeridge Woods at a depth of 556 yards. The 
seam is 20 feet thick, and beds of excellent ironstone have 
also been encountered. The discovery has verified the pre- 
diction of geologists regarding the existence of Coal- 
measures under the sandstone to the west of the South 
Staffordshire coalfield. This is the first place where coal 
has been found on the eastern side of the great Western 
Boundary fault, and the discovery is one of national import- 
ance. The work of sinking was commenced nine years 
ago, and great difficulties had to be contended with in 
consequence of the large quantities of water encountered. 
Tue Transvaal Geological Survey has issued a mono- 
graph (Memoir No. 3, Pretoria, 1906, price 7s. 6d.), by 
Mr. E. T. Mellor, on the geology of the Transvaal Coal- 
measures, with special reference to the Witbank coal- 
field. It contains a detailed account of the coal resources 
of the Witbank district, at the present time the most 
important coalfield in the Transvaal. In addition, the 
available information regarding the geology of the Coal- 
measures of the Transvaal in general is ably summarised. 
Notes on the correlation of the Transvaal Coal-measures, 
a list of the fossils of the Transvaal Coal-measures, analyses 
of the coals, statistics of production from 1893 to 1906, 
and a useful bibliography are appended. The memoir 
covers sixty pages, and is accompanied by a map, six 
sections, and fourteen plates reproduced from photographs. 
In the Engineer of February 1 there is a copiously illus- 
trated description of the Tehuantepec railway and of the 
terminal harbours at Salina Cruz, on the Pacific, and 
Coatzacoalcos, on the Gulf of Mexico, which were formally 
opened by the President of the Republic of Mexico on 
January 23. The length of the line is 189 miles, and the 
Opening up of a trade route across the isthmus will be of 
special benefit to the middle’ west of the United States. 
The average saving in distance by the Tehuantepec route 
over a Panama canal for traffic between Europe or the 
Atlantic ports of the United States is about 1250 miles. 
NO. 1945, VOL. 75| 
| 
Proposals to construct a railway across the isthmus were 
made as long ago as 1842, and a railway was completed 
by 1894, the Mexican Government having spent on the 
undertaking 3,500,000l1. The railway, however, was not 
adapted for heavy traffic, and had no terminal facilities 
or harbour works. In 1898 the Government entered into 
a contract with the London firm of S. Pearson and Son, 
Ltd., to reconstruct the line and to provide harbour 
accommodation. This has now been done at a cost of 
9,500,0001., and the railway will undoubtedly prove a 
formidable competitor to the Panama Canal when that 
difficult enterprise is completed. For the Panama Canal 
the Americans have decided on a lock-canal system; but 
this system cannot, Mr. P. Bunau-Varilla points out in a 
very important paper contributed to the Society of Arts 
(Journal, vol. lv., p. 239), be looked forward to with com- 
placency in a volcanic neighbourhood subject to earth- 
quakes. Mr. Bunau-Varilla, who had been connected with 
the Panama Canal since 1884, proposes a well-considered 
alternative scheme in which water is used as the carry- 
ing power for the machinery to do the excavating and for 
the transport of the dredged material. In short, the 
heavy rainfall is not treated as an enemy, but converted 
into a friend and ally. In this way Mr. Bunau-Varilla 
claims to have solved the problem set by Charles V. in 
1523 to Cortes: Discover the secret of the straits (el 
Secreto del Estrecho). The secret lies in the topography 
and hydraulics of the isthmus. Everything has been pre- 
pared by nature, in the high valley of the Chagres, to lift 
the earth that obstructs the site of the straits. Harness 
this power, and the straits will be made by its spontaneous 
action. 
In a document issued by the Public Works Department, 
the director of the Zoological Gardens at Giza announces 
that he has returned from a trip to the Sudan, bringing 
with him a number of animals, inclusive of a giraffe, 
three young elephants, and five ril gazelles (Gazella 
ruficollis). 
Havinc in earlier issues of the same journal discussed 
the filtering apparatus attached to the gill-rakers of 
various groups of surface fishes, especially those which 
feed on plankton, Dr. Enoch Zander in part ii. of vol. 
Ixxxv. of the Zeitschrift fiir wissenschaftliche Zoologie 
records the results of his investigations in connection with 
corresponding structures in deep-sea fishes. The general 
results arrived at in the case of surface-dwelling species 
hold good in the main for deep-sea fishes, forms living in 
open water usually having the filtering apparatus much 
more strongly developed than in the bottom-dwelling types. 
The large-headed open-water genus Stomias is, however, 
an exception in this respect. 
In the American Naturalist for January Mr. E. Linton 
describes the manner in which the parasitic fish Fierasfer 
affinis effects an entrance into the body of the sea- 
cucumber, which serves as its host. Although the obsery- 
ations are not entirely new, they are of considerable 
interest. When the small pellucid fish comes alongside of 
the holothurian, it gradually feels its way down the body 
of the latter by means of its head until it reaches the 
vent, when it immediately curls itself into a loop and 
thrusts the tip of its whip-like tail into the aperture of 
the latter. When this is accomplished, the fish straightens 
its body, and proceeds leisurely to insinuate itself, tail-first, 
into the body of its host, the action being apparently 
assisted by the spines of the dorsal and ventral fins. The 
whole process occupies only about half a minute. 
