NOTES AND ABSTRACTS. 
221 
portion of it can reproduce itself; it is uninjured by heat or drought or forest 
fire, the leaves springing up again and growing an inch a day, and the author 
has seen it growing in the sulphurous smoke of a volcano in Java. — G. D. L. 
Endothla parasitica and Related Species. By C. L, Shear, N. E. Stevens, 
and R. J. Tiller (U.S.A. Dep. Agr., Bur. PI. Ind., Bull. 380, Jan. 1917, pp. 1-80 ; 
5 figs:, 23 plates). — The importance of this group of fungi was first recognized when 
the chestnut blight fungus was discovered in 1904. 
Endothia gyrosa (Schw.) Fr., the type of the genus, is divided into two sections. 
In section 1 the ascospores are short and pseudoseptate. There are two species: 
E. gyrosa found on five hosts — Castanea, Fagus, Quercus, Vitis, and Liquidambar ; 
and E. singularis found on Quercus. 
In section 2 the ascospores are oblong, fusiform, and uniseptate. There are 
four species and one variety, as follows : 
Endothia fluens found on Castanea and Quercus in America, but in Europe 
has been found on Alnus, Carpinus, Ulmus, Corylus, Aesculus, Fagus, and Juglans. 
Endothia fluens mississippiensis is only found on Castanea and Quercus, 
Endothia tropicalis found 'on Elaeocarpus, Endothia longirostris, and Endothia 
parasitica, which is found on Acer, Carya, Quercus, Rhus, and Castanea. On 
the last named it is actively parasitic, and is the cause of the chestnut blight. 
A list of literature referring to this fungus is appended. — A. B. 
Exosmosis, Studies on. By S. C. Brooks (Amer. Jour, Bot. Nov. 1916, vol. iii. 
No. 9, pp. 483-492). — The author points out that osmotically active substances 
may diffuse out of the cell, and this diffusion should be carefully noted in ex- 
periments on permeability when the turgidity of plant cells is used as a standard. 
This is often overlooked, and is an important source of error. 
The conclusions drawn from a number of carefully devised experiments 
with the peduncle of Taraxacum officinale and specially prepared reagents 
are as follows : 
Sodium salts increase the rate of exosmosis of other electrolytes from the 
protoplasm of Taraxacum officinale, while calcium salts reduce this rate. 
A solution may be prepared consisting of a mixture of various salts in pro- 
portions such that, when used at a concentration isotonic with the protoplasm, 
it causes no appreciable alteration in the permeability of the plasma membrane 
of Taraxacum officinale. — A . B. 
Farm Manures, Composition and Value of. By O. F. Jensen {U.S.A. 
Exp. Stn. Mich., Circ. 25, May 1915). — A useful treatise on farmyard manures, 
their values (1) as plant foods, (2) in relation to the kind of food given to animal, 
i.e. the value of certain foodstuffs when given to the animal, from the point of 
view of manure returned to the farmer. 
The author states that the value of animal manures is not so much in their 
fertilizer content per ton, although this is very important, but owing to the 
humus present they make a great alteration in physical condition, by the power 
they have of increasing the aeration, warmth, and water-holding capacity of soils, 
and also their lasting effects. — C. P. C. 
Farm Manures, Losses and Preservation of. By O. B. Winter (U.S.A. Exp. 
Stn. Michigan, Circ. 25, May 1915). — The author shows that under the best possible 
conditions at least 15 per cent, to 20 per cent, of the fertilizing elements are lost, 
but under the usual conditions in most farms as much as 50 per cent, is actually 
thrown away. 
The worst floor for stables is one of puddled clay, closely followed by planks. 
It is suggested that all stables should have a water-tight bottom running down 
to a tank at rear. 
Another heavy cause of loss is the practice of placing manure in heaps in 
the fields, and allowing such heaps to stand exposed to the weather. 
Absorbents recommended for the prevention of avoidable losses are straw, 
fine earth, peat. — C. P. C. 
Ferns, Eradication of, from Pasture Lands. By H. R. Cox (U.S.A. Dep. 
Agr., Farm. Bulletin 687, Sept. 1915; figs.). — The hay-scented fern (Denn- 
staedtia punctilobula) and the brake fern (Pteris Aquilina) have become serious 
pests in pasture land in the United States. 
This bulletin gives an account of attempts to exterminate the hay-scented 
fern in the Eastern States. Spraying, cutting, and burning were all tried. In 
most situations cutting, or cutting and burning, are in practice the most effica- 
