516 
POPULAR SCIENCE REVIEW. 
combined with other circumstances, Professor Oliver thinks, favours the 
idea that a migration of forms has taken place north of the Pacific, by an 
overland communication, which may have existed during the tertiary epoch, 
somewhere about Behring’s Straits, or the line with the Aleutian islands ; and 
to this cause is probably due the community of types in the Eastern states of 
North America and the Miocene of Europe. 
Distribution of Fungi. — The eminent mycologist M. Fries remarks that 
the lowest forms, as Penicillium, may be found alike on the Alps of Lapland 
and in the Libyan desert ; while, for the higher forms, heat and humidity 
are peculiarly necessary. Hence the Hymenomycetes and Gasteromycetes 
only appear when the weather is peculiarly favourable, or after abundant rams. 
Heat, however, is more essential for plants of higher organization than for 
ungi, inasmuch as many higher species of Agaric flourish at the close of 
autumn. M. Fries recognizes the existence of two zones peculiar in their 
fungaceous growth — a temperate and a tropical zone. In the temperate zone, 
the Fungi are distributed in a very uniform manner ; while in the tropical 
regions there appears to be a more special plan of diffusion in the several 
countries. The whole of the rather long paper of this illustrious and lamented 
mycologist is well worthy of perusal, and of the highest interest. It will be 
found in the “ Annals of Natural History” for April, having been translated 
from the “ Annales des Sciences Naturelles.” It originally appeared in the 
“ Transactions of the Academy of Upsala.” 
Potato Disease. — M. Fries observes that this disease is accompanied by the 
growth of several species of Mucedo ; but their presence, nevertheless, is evi- 
dently nothing more than the consequence, and not the efficient cause of the 
morbid affection. 
New British Mosses. — Mr. W. Wilson, of Warrington, announces Bartramia 
ccespitosa (Schimper), a Swedish species, in a new marshy spot near that 
place. Hypnum Eugijrium (Schimper) has been found by Dr. Wood, of 
Manchester, near the Rumbling Bridge, Fifeshire. There are only one or 
two other British stations known. Several other mosses have been recently 
added. 
Vegetation of the Island of St. Paul. — The Austrian exploring expedition 
in the “ Novara ” having investigated the botany of this remarkable island, 
the results may be summed up in 56 species of plants, independent of moss, 
besides a few introduced, cultivated species. The former consist of 11 
aboriginal flowering plants (of which 6 are grasses and 1 a rush), 2 ferns, 
1 lycopodium, 3 mosses, 2 liverworts, 4 lichens, and 33 algae. The only 
mould on this island is formed by the decay of the plants, chiefly the grasses, 
yet it is in some places several feet thick. 
The Cotton Plant. — The cultivation of cotton in other countries than the 
Southern states of America is a subject of much interest. On the banks of 
the river L’Habras, in Algeria, is a vast plain, containing about 650,000 
acres, on most of which cotton would grow. Extensive works for irrigating 
this district are in the course of construction, and several companies (one of 
them English), as well as private individuals, are already making a start in 
this promising field. The climate is healthy, excepting that during August 
and September ague prevails, which may, however, be in in a great measure 
avoided with due care ; and labour is very cheap. 
