NOTES AND ABSTRACTS. 
Peas, Heat- Resistant Organisms in Cold-Packed Tinned. By R. Normington 
(U.S. A . Exp. Stn. Mich., Bull. 47, Nov. 1919, pp. 1-34). — A careful bacteriological 
examination of numerous tins of preserved peas which had " swollen," showed 
that all the organisms present were spore-forming bacteria, and these could with- 
stand 10 to 15 lb. pressure in the autoclave for ten to twenty minutes. Seven of 
the bacteria could cause peptonization in milk, and nearly all them could reduce 
starch to sugar. B. suhtilis, B. ramosus, B. ruber, B. prodigiosus, and B. viscosus 
produced gas in peas but not in other media. A chemical examination of the 
spoiled peas showed the presence of creatinin and ammonia. Most of the bacteria 
are soil bacteria and are probably introduced into the vessels from earth on the 
seeds or pods. Cleanliness is obviously the remedy for such losses. A short 
bibliography is appended. — A. B. 
Peas, The Black Hilum of. [Observations faites t Verrieres par Philippe de 
Vilmorin sur le caractere * Hile Noir * chez le Pois.] By A. Meunissier 
{Jour. Gen. x. pp. 53-60 ; July, 1920). — Seven types of peas with a dark hilum 
were grown and the behaviour of the seedlings as regards this character is recorded. 
F. J. C. 
Plant Growth, The Effects of Certain Organic Compounds on. By M. J. 
Funchess [U.S.A. Exp. Stn. Alabama, Bull. No. 191, June 1916, pp. loi- 
132 ; 8 plates). — The causes of fertility or infertility of soils are usually explained 
in terms of plant food or physical condition of the soils. Unproductive soils 
were held to be deficient in some element necessary for plant growth, and this 
could be remedied by applications of fertilizers. 
In recent years, however, the theory that injurious substances harmful to 
plant growth, rather than deficiencies of plant food, are the actual cause of 
unproductive soils has been advanced by the Bureau of Soils, U.S. Dep. of 
Agriculture. These harmful substances are root excretions or products resulting 
from organic decompositions in the soil. Therefore, to restore fertility to such 
soils, the injurious compounds must be removed or rendered harmless. Experi- 
ments have been made and the following conclusions arrived at : 
(1) Poor soils are not benefited by application of carbon black, pyrogallol. 
or calcium carbonate. 
(2) Coumarin and vanillin when added to soils are toxic to plants only in 
large amounts, and when these large amounts are applied at seedling time, 
(3) Nitrogenous compounds like pyridine and quinoline are beneficial rather 
than harmful, and the beneficial effects are increased if potassium and phosphorus 
are added. This is due to the increased effect of asparagin, nucleic acid, and 
nitrate of soda. 
(4) Normal soils are able to dispose of enormous quantities of organic com- 
pounds through physical, chemical, and bio-chemical action. 
(5) Soils very deficient in nitrogen are not much benefited by addition of 
lime, phosphorus, or potassium. Nitrogen alone is much more effective than 
a combination of these compounds. — A. B. 
Plants, Experiments with Soft-Wooded. By Spencer U. Pickering [Woburn. 
17th Report, 1920, pp. 7-76 ; 2 figs.). — Soft-wooded plants were subjected to 
the action of the surface growth of grass and other plants, and the conclusion 
was arrived at that the deleterious effect of one crop on another is a general 
action applying to all plants ahke, from which it follows that the growth of any 
plant must be affected to a certain extent by the toxin which it itself forms 
(PP- 7-29). The nature of the toxin is still unknown. There is no reason to 
assume that it is an exudation from the roots, but it may be a constituent of the 
debris of the growing roots, soluble and easily oxidizable to a plant food, but 
toxic before it is oxidized. The effect of grass on trees is but a particular instance 
of the action of one crop upon another, and it has been demonstrated that trees 
have a similar effect upon grass and other crops, the action in the case of Brussels 
sprouts not being expHcable by the shading of the ground or the exhaustion of 
the soil (pp. 32-36). 
The toxic action of one plant on another plays a prominent part in 
the behaviour of similar plants when massed together. With plants of the same 
age grown in pots it was found that the amount of plant growth produced where 
the mass of soil available was below a certain limit was independent of the member 
of plants grown, i.e. the weight of individual plants was proportional to the 
area occupied by them. If, however, some of the plants were younger than 
the others the total growth produced might be as much as 20 per cent, below 
the maximum possible in the limited mass of soil, a result held to be due to the 
action of toxicity produced by the older plants preventing the younger ones 
