600 

capable of surviving the winter and infecting the 
young wheat in spring. Breeding from plants pos- 
sessing mechanical or other advantages tending to 
prevent the attacks of fungi is, however, as Dr. Appel 
suggests, likely to prove one of the most fruitful 
methods of controlling disease in plants. 
Tue Journal of the Royal Horticultural Society 
(vol. xl., part 3) contains several useful horticultural 
papers, and one of particular interest on the double 
stock, its history and literature, by Miss E. R. 
Saunders. The double stock is referred to first by 
Dodoens in 1568, and is figured by de 1’Obel in 1581. 
Speculations as to the origin and mode of production 
of double stocks have been varied and frequent, and 
it is only owing to the Mendelian methods of analysis 
that light has been thrown on the subject. It appears 
that there are two fundamentally distinct types of 
single stocks—one of which gives rise only to single 
stocks, and the other which yields both doubles and 
singles, the proportion of doubles being from 53-57 
per cent. How the doubles arose from the race of 
singles some two hundred and fifty years ago is un- 
known, but the ratio of doubles to singles yielded by 
these singles appears to be constant for all strains. 
In these ever-sporting singles it has been proved that 
all the pollen grains and some of the ovules lack a 
factor which produces singleness, and by the mating 
of such deficient pollen grains and ovules together the 
double-flowered form results. It has further been 
found that the double-flowered seedling grows more 
strongly than that of the single-flowered plant. 
AN official guide to the Botanic Gardens, Dominica, 
has recently been issued (price 6d.), to which we would 
direct the particular attention of all interested in 
botany and in the tropical economic products of the 
world. The guide consists of some forty-four pages, 
with a good index, a map of the gardens, and a 
number of interesting illustrations. The area under 
cultivation. is now about 60 acres, and consists of the 
garden proper of 44 acres, with experiment grounds 
and nurseries. In the latter are raised the lime, cacao, 
mango, Para rubber, coffee, and other plants, which 
are supplied at cost price to the planting community, 
and it is here that the grafting of cacao, limes, etc., 
and other experiments are carried out which have 
made the Dominica Gardens renowned. To the 
botanist, however, the garden proper is the more im- 
portant feature. Here may be seen a multitude of 
interesting and useful trees and shrubs remarkably 
well grown and displayed, and in the guide particulars 
of the various plants and notes on their economic value 
are given. In 1892, a year after the garden was 
formed, Mr. Joseph Jones was sent out from Kew, and 
has now been curator for thirty-three years. It is to 
his skill and devotion that Dominica now possesses for 
its size one of the finest tropical botanic gardens in the 
world. Mr. Jones is to be congratulated on having 
produced so excellent and useful a guide, which will 
be much appreciated. 
DurinG the past seven years the Canadian Govern- 
ment has published several reports on the peat bogs 
of the Dominion and the efforts it has made to develop 
NO. 2387, VOL. 95] 
NATURE 


[JuLy 29, 1915 

the peat industries (v. Nos. 30, 71, 151, and 154). A 
report now before us (‘‘Investigations of the Peat 
Bogs and Peat Industry of Canada, 1911-12,” by A. v. 
Anrep; Department of Mines, Canada, No. 266, 
Bulletin No. 9) deals with the amount and 
the quality of the peat contained in nine bogs 
situated along the line of the River St. Law- 
rence in the province of Quebec. It gives surface 
and section-maps of the bogs, and includes a detailed 
examination of the quality of the peat over the whole 
range of the bogs, which cover an area of about 
34,000 acres. The portions of the various bogs suited 
for the manufacture of peat-moss litter on the one 
hand, or peat fuel on the other, are indicated on the 
maps which accompany the report. The author also 
considers in detail the engineering and commercial 
problems connected with the utilisation of the peat in 
the case of each bog. Although the report is 
primarily of local interest, one cannot fail, on reading 
it, to be struck with the contrast between the thorough- 
ness with which the Canadian Government is 
grappling with the peat question and the apathy of 
the Irish Government towards the same _ problem. 
Interesting statistics of the peat industries of 
Sweden, Denmark, Holland, and Russia are given. 
Apart from the fact that Russia uses from 23 to 
4 million tons of peat fuel yearly, it is of some interest, 
especially to Irishmen, to learn that the Holmgaard 
factory at Naestved, in Denmark, uses about 5000 tons 
of peat briquettes yearly in the manufacture of glass. 
Tue Royal Observatory at Hong-Kong has issued 
its report for 1914, dealing with meteorological, mag- 
netic, and time observations. The principal features 
of the weather during the year are said to be the 
absence of violent typhoon winds, the relatively high 
temperature in January, February, and March,. and 
excessive rains in July, September, and November, 
with a relatively dry August, and a rainless January. 
The highest temperature was 94° on August 31, com- 
pared with 97° for the previous thirty-one years, and 
the lowest temperature was 47° on January 1, com- 
pared with 32° in previous records. July was by far 
the wettest month, with a rainfall of 26-31 in., and 
the total for the year was 100-22 in. The greatest 
wind velocity for any hour was forty-two miles on 
September 3, and the greatest squall velocity on the 
same day was at the rate of forty-eight miles an hour. 
A map of the Far East and the Daily Weather Report 
is regularly issued, containing observations from about 
forty stations in China, Indo-China, Japan, and the 
Philippines. A daily weather forecast is also given 
for Hong-Kong and district, the Formosa Channel, 
the south coast of China between Hong-Kong and 
Hainan, and the south coast of China between Hong- 
Kong and Lamocks. 
Tue recently published Compte rendu of the 
Physical and Natural History Society of Geneva 
for the year 1914, shows that the activities of the 
society have not been seriously affected by the war. 
The society consists of sixty-six ordinary members and 
about the same number of honorary and free mem- 
bers. The scientific papers for the year cover sixty- 
