382 
THE MEDITERRANEAN NATURALIST 
tribute the origin of the great lake basins 
of Switzerland to the action of Glaciers. 
Prof. Bonney holds that these great lake 
and rock basins owe their origin to sub- 
serial influences assisted by differential earth 
movements, and that the glaciers which at 
present occupy them do no more than mo- 
dify the more prominent physical features 
of these basins. 
m 
|, HE unusually dry weather which has 
prevailed in and around the Mediterranean 
during the last two months has caused con- 
siderable distress in the agricultural dis- 
tricts. It has not however, been an altoge- 
ther unmixed evil. The vines in both Sicily 
and the Maltese Islands have been, are still 
are remarkably free from all trace of the 
malignant Peronospera which effected such 
wholesale devastation last year, a fact that 
is to be attributed to the absence of those 
humid atmospheric conditions wdiich cha- 
racterized the months of April and May 
1892. 
J, HE Aphiclidce have been usually abun- 
dant and destructive in the Maltese Islands 
during the recent Winter and Spring months. 
The beans, peas, fruit-trees, and in fact 
every kind of agricultural produce have 
suffered, and still are suffering to a greater 
or lesser extent from their attacks. These 
minute pests derive the greater portion of 
their food supply from the juices of the 
leaves and blossoms, and by thus preventing 
the leaves and blossoms from performing 
their proper functions, they retard their 
growth and diminish the quantity and qua- 
lity of the crop. 
Thanks, how r evcr, to the endeavours of 
those industrious mites of creation known 
as the Coccinellidce the prospects of the 
Maltese farmer though heavily handicapped 
by his numerous foes, are not ’entirely 
hopeless. Several species of the family of 
the Coccinellidce, known among the Mal- 
tese by a variety of names such as Bestioli- 
ne del Signore . Saibella and Cola , have this 
year been also unusually abundant, and as 
yJ O 
these little creatures are the inveterate 
enemies of all scale insects , aphides, and 
parasitic fungi , they have assisted greatly 
in minimising what at one period of the 
year threatened to become a serious scourge 
to the Maltese agriculturist. 
The enormous amount of good that they 
are capable of doing for the agriculture of 
the islands in general, and for the fruit gro- 
wers in particular is incalculable, and every 
farmer should therefore, consider is a sacred 
duty to see that these little friends are fos- 
tered and protected. Great quantities of 
them are at present at work in the orange 
groves of Musta, St. Antonio, and Boschetto 
devouring the scales vdth which the olean- 
ders, the orange, and other trees are covered. 
ik hew work by Mr. H. M. Wilson states 
that by irrigation 25,000,000 acres are made 
fruitful in India alone. In Egypt there are 
about 6,000,000 acres, and in Europe about 
5,000,000. The United States has but just 
began the work of improving its waste area, 
but has already about 4.000,000 acres of 
irrigated lands. 
Jt has been known for several years that 
the germs of some diseases pass unharmed 
through the digestive system of flies. A 
German bacteriologist has now added Asia- 
tic cholera to the list of diseases, finding 
that the cholera Bacteria may survive 72 
hours, or even longer, in the intestines of 
flies, while it is probable that under some 
conditions they may multiply there. 
In mountainous regions erosion produces 
such rapid and disastrous changes that the 
Swiss Government is seeking to regulate the 
torrents of that country. A frequent source 
of floods is the damming up of a large river 
by the mud and stones brought down by a 
freshet in a small tributary. This danger is 
avoided by building a succession of weirs 
and cutting a parallel canal, the sediment 
being thus caught and the overflow regula- 
ted before the water reaches the main valley, 
