H.—29.

leg, the wing, the head, or even from a wing-feather follicle. When bleeding commences it is kept going by pecking of the area either by the bird affected or by others in the flock until the affected bird is so weak that it naturally stops bleeding, or may even die. The coagulation time of the blood is not interfered with, calcium in the blood is normal, and blood platelets are not lacking. On several occasions blood-effusions beneath a scale of the leg have been seen and have been opened. If treated in this way the bird lias not taken much notice of the wound. As the condition is comparatively new, and could not be ascribed to parasites, to food, or to blood chemical deficiencies, an experiment in breeding is in progress. BIOCHEMICAL WORK. Mr. S. W. Josland, who is in charge of this section of the work, reports as follows : — " Up till 1930 no organized biochemical work had been carried out on the blood and urine of normal sheep and cattle in New Zealand. The first problem, therefore, to be attempted following the institution of the biochemical laboratory was the determination of normal values or limits for the purpose of standards which may be considered as a groundwork upon which future biochemical investigations may be based. This task has formed the basis of the past year's work. In addition, biochemical work has been directed towards several diseases of sheep and cattle. This aspect was discussed briefly when the diseases concerned were being considered. " Source of Material. —Blood and urine samples were collected from the Laboratory farm animals and also from the Gear Meat-works at Petone. The samples were taken from the jugular vein by means of a wide-bored hypodermic needle (internal diameter 1 mm.) and collected in plain bottles and bottles containing potassium oxalate as an anticoagulant-. The samples thus taken were examined both chemically and histologically. " Chemical Methods. —Estimations have been made of the following blood-constituents : Serum Oa, serum P 2 0 5 , serum Mg., serum K., T.N.P.N., urea N., amino acid N., creatinine, uric acid, cholesterol, and sugar. " Particulars of the methods adopted are given below : — "Calcium: Kromer and Tisdall, Clark and Collip. Joum. Biological Chemistry, 56, 439. 1923. " Inorganic Phosphate : Fiske and Subbarrow. Joum. Biological Chemistry, 66, 375. 1925. "Magnesium: Denis. Joum. Biological Chemistry, 52, 411. 1922. "Potassium: Kromer and Tisdall. Joum. Biological Chemistry, 46, 339. 1921. " Cholesterol: Myers and Wardell, modified. Joum. Biological Chemistry, 26, 147. 1918. " The remaining constituents were estimated on a protein-free filtrate prepared according to the method of Folin and Wu, but using increased volumes of sod. tungstate and sulphuric acid, with a corresponding decrease in the volume of distilled water. " Blood sugar : Benedict's modification of Folin and Wu. Joum. Biological Chemistry, 68, 759. 1926. " T.N.P.N. : Micro Kjeldahl. " Urea N. : Karr's direct nesslerization. Karr. Joum. Lab. Clin. Med., 93. 1924. " Amino acid N. : Folin and Wu. Joum. Biological Chemistry, 51, 377. 1922. " Creatinine : Picric acid method. Hawk. Practical Phys. Chem, 375. 1929. "Uric acid: Folin's isolation procedure. Joum. Biological Chemistry, 54, 153. 1922.

"Normal Limits for Blood (Values in Millegrammes 100 per c.c.).

* Owing to the delay in obtaining the necessary reagents, a limited number of these estimations were made. These values must be regarded as provisional. " It will be pointed out that certain blood-constituents undergo marked changes in certain physiological processes such as pregnancy and oestrus. An endeavour is being made for the forthcoming year to trace these changes in a detailed manner. " Urine Analyses. Sheep. Cattle. "Sp.G. .. .. •• •• •• 1,010-1,030 1,010-1,030 "pH .. .. • • • ■ • ■ ■ • Approx. 7-5 Approx. 7-5 " Albumen .. .. .. ■ • • • Nil.* Nil.* " Sugar .. .. .. . • ■ • Nil. Nil. " Acetone .. .. • • • • • • >> >> " Diacetic acid .. .. .. •• >> >> " Urobilin . . • • ■ • • ■ • • >> >> " Urea .. .. . • • ■ • • • • Approx. 2-0% Approx. 2-0% " Ammonia nitrogen .. .. • . . • 4-20 mgm. per 100 c.c. "Total nitrogen.. .. •• •• 1,000-1,500 1,000-1,500 * Traces of albumen are occasionally found in urines from apparently normal cattle. Such traces are generally considered to be of a transitional nature. "Deposits: Usually nil. Occasionally unorganized sediments are present depending on variation of reaction. There is an absence of organized sediments such as pus, blood, and epithelial cells and casts."

55

j Sheep. | Dogs. Cattle. Calcium .. .. •• •• 10-11-5 10-5-11-5 10-11-5 Inorganic phosphate .. .. .. 4-5-5-5 .. 4-5-5-5 Magnesium* .. • • • • 1-5-2-5 2-5 Potassium* .. .. . . .. 17-26 20-25 T.N.P.N. .. .. - • • • 28-38 30-35 28-38 Urea N. .. . - - - •• 14-20 12-17 12-17 Creatinine .. .. .. . • 1-2 1-2 1-2 Amino acid N.* • • • • • • 5-8 Uric acid* .. .. .. • • 2-5-3-5 2-5 Chlorides .. . . .. . ■ 450-550 . . 450-500 Sugar .. . . . • ■ - 0-050-0-065% 0-060% 0-050-0-060% Cholesterol .. • ■ ■ ■ ■ • 90-110 .. 90-130 Hb . . .. .. .. 70-80% 85-95% Approx. 60% Erythrocytes .. .. .. 10-11 mils, per c.mm. 5|-6J mils. mils. Leucocytes .. .. .. .. 6,000-8,000 8,000-12,000 5,000-7,000 Polymorphs .. .. . . .. Approx. 30% Approx. 60% Approx. 35% Lymphocytes . . . . •. ,, 65-5% ,, 37% ,, 58% Eosinophiles.. .. ... .. „ 4% ,, 3% ,, 7% Basophils .. .. .. .. ,, 0-5%