The use of herbicides and insecticides in agricultural practices may influence, directly or indirectly, both the microflora of the soil and the development of plants. Because of the increasing use of compounds of this nature in agriculture it is imperative that such effects should be studied to avert possible damage to large sections of arable land. [...]

Bacteria and other micro-organisms play a very important role in the alteration and decomposition of proteins in nature. Although the proteolytic enzyme systems of animals have been fairly well studied and classified, comparatively little is known about these systems in micro-organisms. [...]

The author claims to have conducted an original investigation into the following aspects of soil fertility: 1. A direct relationship between microbial numbers and CO2 evolution in two soils; one a mineral soil and the other a muck soil. [...]

Moulds belonging to the Fusarium genus were isolated that are able to utilize coumarin as the sole carbon source in a medium containing inorganic nitrogen and various salts. Factors affecting the growth of the cultures and the rate of coumarin degradation were studied. [...]

In the last fifty years many investigators have studied the microorganisms that are in the soil which surrounds the roots of living plants. Some of them endeavoured to provide a better understanding of the various phenomena related to plant feeding and growth, cropping systems and root disease control, but others tried to establish the nature of the microorganisms and to note the differences from those in soil not in the immediate vicinity of the plant root.

"The forest wealth of Canada is one of the country's greatest natural resources. Our forests have often been termed inexhaustible and perhaps they might be, were it not for the annual losses caused by fire, insects, disease and industrial use. Insects and diseases are responsible for the loss of at least 500 million cubic feet of timber annually or about 15 per cent of the annual depletion." [...]

The organic forms of nitrogen in the soil are derived largely from plant residues, such as stubble, weeds, leaves, and pine needles etc. The amount of protein in these organic materials is often very large. For example, the protein content of cereal straw and wood shaving may be as much as 2 or even 15 per cent, and the protein content of certain defatted meals, may be 40 or even 60 per cent. The phenomenon of growth and death of bacteria in ordinary culture media has been studied in considerable detail.

The need for sanitary control of molluscan shellfish resulted from the use of rivers, streams, and the sea for the disposal of sewage. Sewage discharged into the sea is rapidly and enormously diluted, but many shellfish beds of commercial importance are situated within long inlets or estuaries where dilution is less effective. In such places molluscs, by virture of their mode of feeding, can become polluted to an extent which make them unsafe to eat uncooked.

Few reports seem to have been published about the numbers and types of bacteria and yeasts that may be found on apples. Indeed, only one study has been made of the types of yeasts found on Quebec apples picked late in the autumn; and there seems to be only one report about changes in the microflora of apples during the ripening season in England. The significance of a study such as this is important with respect to the keeping quality of the fruit, the production of cider, and the preparation of canned products, such as apple sauce and apple juice.

In 1943 Lochhead and Chase (97) devised a system of nutritional classification of soil microorganism which has since proved to be of considerable value as a method of characterizing the soil microflora and hence of studying changes in the distribution of the nutritional groups of organisms comprising the flora, under different soil conditions. The procedure used by these workers, which was based upon the growth response of individual soil isolates in six nutritional media, proved to be cumbersome in the laboratory, largely because of the necessity of using one hundred or more isolates from each soil sample to obtain statistically valid results.