The nitrogenous substances or albuminoids, of which animal tissues for the most part consist, and which are also found in the seeds, leaves and other parts of plants, were originally believed to be composed of one and the same organic substance called protein by Mulder about a century ago (from πρωτɛύω “I am the first”).

A study has been made of the nitrogen distribution in Kingston cheese, over a ripening period of 98 days. For the determinations, methods evolved and employed by Orla-Jensen, Barthel and others have been drawn upon. In addition, a departure has been made in applying to this study the method developed by Wasteneys and Borsook for the fractional analysis of incomplete protein hydrolysates.

Determinations were carried out on cheese of the same “make” from the day of making to the 98th day of ripening at intervals denned and recorded in the tables and figures.

Results obtained when employing the methods of Orla-Jensen and of Barthel have been complemented by the application of the Wasteneys and Borsook method, which defines the nature and the amount of various protein decomposition fractions (proteose, peptone and sub-peptone) formed as the ripening of the cheese proceeds.

Particularly striking is the finding that the difference in the results of the amide nitrogen determinations and the amino nitrogen determinations can be explained when interpreted in the light of data secured by the application of the method of Wasteneys and Borsook. The amide nitrogen curve has been found to coincide with the sub-peptone nitrogen curve, and the amino nitrogen curve to superimpose itself upon the curve depicting the sum of the subpeptone nitrogen and the peptone nitrogen.

The results of our study, subject to qualification as further data on the nature of specific enzymes may appear, suggest that after the first few hours of ripening the proteolytic breakdown in the ripening of Kingston cheese is of an associative peptic-tryptic-like nature.

1. A method is described for following the intensity of reduction (or oxidation-reduction potential) at different levels in the interior of ripening Cheddar cheese.

2. Variations in this potential throughout the course of ripening are described and mean values assessed.

3. Cheese are shown to be not homogeneous throughout their mass; outer zones of more highly oxidised condition exist near the surface of the cheese and round cracks and borings. The depth of these zones increases with the age of the cheese.

4. The values obtained can be correlated with the known bacteriological data for Cheddar cheese.

5. The significance of the data obtained in relation to cheese faults is discussed.

Traces of heavy metals in amounts up to 25 parts per million have the property of inhibiting the action of lipase in butter from unpasteurised sweet cream in varying degrees depending on the concentration of the metal and on the metal itself. Copper was the most potent metal of those studied, iron, nickel, cobalt, manganese, and chromium being less active, while tin and aluminium had no effect.

The acidity produced was accompanied by fat-peroxide formation in amount varying directly with the acidity. This was attributable to the free oleic acid formed.

The depression of lipase activity by the various metals varied directly with their catalytic power in inducing fat oxidation later, and it is suggested that destruction of lipase was catalysed by the traces of heavy metals according to their varying powers of activating oxygen. Lipase as a compound naturally associated with fats might thus be looked on as a natural “antioxygen.”

The development of the factory-cheese industry in this, and other countries, is handicapped by the wastage of the by-product. In Great Britain alone, approximately 20,000,000 gallons of whey are produced annually by cheese factories(i), and most of it is thrown down the drains. When it is considered that whey, which constitutes half the valuable food material of milk, is so wasted, the development of the industry to even its present dimensions is a matter for surprise.

This study is a continuation of the investigations of Prof. Agar, Professor of Zoology, University of Melbourne, entitled “Heredity and milking function,” which appeared in the Journal of Agriculture of Victoria in January, 1926; and it deals with the inheritance of milk, butterfat percentage, and butterfat in the Victoria Stud of Red Poll Cattle owned by the Department of Agriculture of Victoria, at the State Research Farm, Werribee. The milk and butterfat records used in these investigations are the 273 day records performed under the regulations governing the Victorian Government Pure-bred Herd Test, published annually, and included in the successive volumes of the Red Poll Herd Book of Australia. They cover the period since the establishment of the Government Herd Test—1912–13 to 1929–30.

A Fresh milk supply is as essential in the tropics as it is in the more temperate regions of the world. The most fundamental of the many problems connected with tropical dairying is that concerned with the establishment of breeds of dairy cattle which will live and thrive in their environment, and produce milk; the intensity of the problem varies with the degree of severity of the climatic and environmental conditions. The manner in which this problem has been dealt with at the Government Stock Farms at Kingston, Jamaica, together with the results, is discussed in the following study. The data were collected by Mr J. Hammond from the records of the herds at these farms. To Mr H. H. Cousins, the Director of Agriculture, who has not only built up the herd to its present state of excellence but has kept also a complete record of the pedigrees and performances of all the animals, and to Dr S. Lockett, Veterinary Officer for the Department, our thanks are due for having put these records at our disposal and for communicating to us the results of their experience.

This article records the preliminary results of an investigation of some of the causes of the variations in the yield and composition of milk. The influence of the season of the year, and the influence of climatic conditions on the average yield and composition of the milk of a herd, are discussed.

The relationships between the data are studied by means of simple corre-lation and also by means of partial correlation. The temperatures used are the average temperatures for the periods between the milkings. Thus the day-temperature is the average temperature of the interval between the morning and evening milking, and the night temperature is the average temperature of the interval between the evening milking and the next morning milking. The daily temperature is the average of these two temperatures.

1. Normal curves of growth for dairy Shorthorn cattle from birth to 5 years of age are presented. These include height at withers, length of body, depth of chest and live weight.

2. The expression of growth by the “Relative growth rate” method is discussed and illustrated. The method is particularly suitable for expressing the growth of calves under 6 months of age.