342 
THE MEDITER liAKEAN NATURALIST 
Picridium vulgare D:sf. 
Chcnopodium urbicum L. 
Trisetum c&ndenscttum Sch. 
Sclerocla rigida Lie. 
Poa annua L. 
Oil walls we find: — 
Reseda alba, L. 
Phagnalon rupestre D.C. 
Antirrhinum siculum Elc. 
Nicotiana glauca Gr. 
Parietaria officinalis L. 
In the country I have seen on terraces many 
other plants, but I am only mentioning those 
which are of the commonest occurrences. 
Of mosses the species which is constantly seen 
on all terraces is Barbula muralis Hedv> in its 
two forms incana and aestiva; it begins to come in 
fruit in January. 
Among the commonest lichens on terraces I 
have noted : — • 
Psorotichia murorum Mass. — which is the first 
to appear on walls looking to the North. 
P.lacodvuin circinnatum Pers. 
Lecanora sulphurea Schaer. 
Ricasolia Gennari Bgl. 
Ricasolia Cesati Mas. 
Amphiloma cattopisma Ac. 
Collopisma luteoalbum Mass. 
Aspicilia calcarea L. 
Verrucaria controversa Mass. 
Lastly those green expansions generally seen in 
the more moist places are due to the presence of 
algae, of which the commonest are: — 
Pleurococcus tectorum Trev. 
„ vulgar e Menegh. 
Protococcus viridis Ag. 
Dr. Alf. Caruana Gatto. 
Science Gossip. 
An instructive map of North Germany, showing 
the distribution of forests and the most common 
species of trees during the Middle Ages, has been 
prepared for a geographical journal by Dr. Ernst 
H. L. Krause. The work has been accomplished 
chiefly by the consultation of old records, and the 
examination of forest remains and ancient trees. 
The increase of population and farm cultivation 
may be strikingly shown by comparing such a map 
with one of modern vegetation. 
From statistics of man’ year'. Dr.' P. J. Kolski 
finds that, though the weather mav nor be rhe 
main cause of kroupous pneumor.:-.. is was for- 
merly believed, it plays a not unimportant part in 
the development of the disease. Abnormal 
weather in general has an influence. In Moscow 
the most favorable condition' for the prevalence 
of pneumonia seem to be a low temperature with 
slight daily variati rurally high barometric 
pressure, a north wind of less than usual force, 
and a small amount of rain or snow. High winds 
and much moisture, contrary to general belief, do 
not favour pneumonia. 
At Bushire, on the Persian Gulf, an extreme 
temperature of 180 : is said to have been recorded. 
Shikarpur, India, at times ha' no place cooler 
than 140,° and at Sukkur the lowest temperature 
is 97°. Here hot winds from the desert are some- 
times so terrible as not only to kill everything in 
their path, but even to burn up tissue and cartilage. 
The Russians claim that Central Asia has places 
even hotter than these. In the southwestern 
United States temperatures of 13(E and 140' are 
not uncommon. 
A study of the records of the last ten years has 
shown Habenicht, of Gotha, some unmistakable 
coincidences between the frequency of icebergs in 
the Gulf Stream and the weather in Europe some 
six months afterwards. The number of icebergs 
reported has varied from 10 in 1888 to 674 in 1890. 
The iceberg minumum of 1888 was followed by 
the warmest year of the series; and the remarkable 
maximum of 1890 was followed by the coldest 
winter and spring known for twenty years. 
The cultivation of sunflowers in Russia was 
begun in 1842 at Varonezh. The industry has 
proved so profitable that in 1881 not less than 
367,800 acres had been given up to it, and in 1887 
the area planted had increased to 704,500 acres. 
The chief product is the oil from the seeds. The 
