The magnitude of experimental error attaching to one or more field plots is a question of extreme importance in Agricultural Science, because upon its proper recognition depends the degree of confidence which may be attached to the results obtained in field work. A very cursory examination of the results of any set of field trials will serve to show that a pair of plots similarly treated may be expected to yield considerably different results, even when the soil appears to be uniform and the conditions under which the experiment is conducted are carefully designed to reduce errors in weighing and measurement.

1. The distribution of Silver-leaf disease is described.

2. Inoculations of branches of Plum trees with sporophores of Stereum purpureum have almost invariably resulted in silvering.

3. The mycelium of Stereum purpureum has been cultivated in pure culture from spores and inoculations with this mycelium have caused silvering.

4. A small number of inoculations with the spores of Stereum purpureum have resulted in silvering.

5. Various series of control experiments have given negative results.

6. The investigations strengthen the view that Stereum purpureum is the active agent which causes Silver-leaf disease in this country.

The important part played by calcium carbonate in maintaining the fertility of the soil makes it of interest to investigate all the causes which determine both its formation and decomposition. A number of processes which are continually going forward in the soil tend to diminish the stock of calcium carbonate present; yet, in spite of this, and without frequent additions of chalk or lime from other sources, most soils, under normal conditions, remain more or less in a state of fertility. An equilibrium is set up by which the withdrawal of calcium carbonate is balanced by the results of another set of actions which restore base to the soil. This enables many soils which contain only very small quantities of lime to retain their neutral reaction and so to produce fair crops.

It is a matter of common experience in dairy work, that different creams vary in their behaviour during the operation of churning; and many theories have been adduced to explain the factors which possibly affect, adversely or otherwise, what may be termed, for want of a more suitable word, churnability

The gradual loss of efficiency of certain alkaline arsenite dipping baths has been traced by Brünnich to the oxidation of the arsenite to arsenate (Australian Association for the Advancement of Science, 1909). In this latter form, arsenic is not nearly so efficacious for the eradication of ticks, as in the reduced condition.

In undertaking a survey of the soils of a given district the methods of analysis and the classification to be adopted (which in its turn shapes the scheme of the work) must be determined by the purpose before the investigator at the outset. His end may be scientific–to assign the soils in question to their types, or practical–to give information to the cultivator by showing him the area over which a given method of treatment may be expected to succeed. Much will depend upon the extent of the area under investigation and on the character of the climate prevailing.