The continuous formation of antibodies over long periods of time after immunization of animals with certain toxoids and bacterial polysaccharide (1, 2), dextran and blood group substances (3), and viruses (4), is well documented. More recently, antibodies of the nonprecipitating type have been shown to persist in the circulation of rabbits following immunization with serum protein antigens (5). In a previous study, it was shown that the non-precipitating antibodies could not be differentiated from the precipitating antibodies on the basis of their electrophoretic, sedimentation and salting out properties (6), although it was demonstrated that they, unlike the precipitating type, could not sensitize guinea pigs to anaphylactic shock in vitro (7).

The Nineteenth Century was marked in Europe and in North America by an increasing awareness of scientific thought which was carried into many fields of human endeavour. It was during this period that the study of medicine began to flower, as interest was awakened in the accurate observation and recording of natural phenomena as they occur in the human body in health and disease. Normal human anatomy was becoming increasingly better understood, the study of pathology was advancing rapidly and the infant physiology was gaining interest. Prior to 1830, acute inflammation of the pancreas had been observed and recorded so seldom that in the minds of most physicians it was a theoretical disease.

The work of Wearn (1933) describing the myocardial circulation, with its myocardial sinusoids and arterio-luminal vessels, was confirmed by Vineberg in 1945. He reported implanting the left internal mammary artery into the wall of the left ventricle. The intercostal branches were open and bled freely into the myocardial tunnel through which the internal mammary artery had been drawn. In no single instance, in either animal or human heart, was there a myocardial hematoma. The implanted arteries not only remained open, but sent out branches which anastomosed with those of the surrounding coronary vessels.

Notwithstanding extensive studies carried out by numerous investigators in this field, the exact mechanism of fat metabolism still remains unknown. However, it would be uncorrect to state that no significant advances have been made in recent years. As a matter of fact, the new methods available have enabled biochemists, pathologists and clinical investigators not only to re-search, (quoting Dr. Skoryna), some of the older findings, but also to throw some light on the intricate processes in fat absorption which were unapproachable by older methods.

Attention has been drawn to the complex problem of the neurogenic bladder by the increased incidence of spinal cord trauma in civilian and war casualties. Improvement in the immediate care of the injuries has resulted in a greater initial salvage rate. The increased population of patients with neurogenic bladders suggests a need for re-evaluating the fundamental aspects of this problem. The physiology and pathology of the normal and neurogenic bladder have been studied. The utilization of substitute bladders in these cases has not been fully explored.

The controversy regarding the cell of origin of white adipose tissue fat cells has not been resolved. It has not as yet been established whether a fat cell represents a modified connective tissue fibroblast which has accumulated lipid (44, 35) or is derived from a specialized perivascular reticular mesenchymal cell (174). The fat cell has been classically described as having a signet ring appearance on histological section due to the peripherally displaced flattened nucleus and the large central vacuole representing the space occupied by fat. A very thin attenuated ring of cytoplasm exists but is not readily apparent by light microscopy.

The production of acute uremia in the experimental animal has been achieved with much success. Various procedures that deal with its production have been described. There are articles in medical literature that have been written on the production of an asotemia or uremia that follows a chrome pattern, yet none deals with it as a process that is prolonged, gradual and sustained, maintaining the experimental animal relatively free of untoward signs and symptoms of the condition produced.

A study of vein grafts used for the relief of venous obstruction of the dog's hind leg was undertaken to find out how feasible and helpful a similar procedure would be in Post-Phlebitic Syndrome in the human. The use of vein grafts implanted into the venous system has had little attention compared to the extensive studies on arterial grafts. It has been established that grafts, both autogenous and of plastic cloth weave, have been successful in major veins such as the superior vena cava and inferior vena cava. Little attention has been paid to veno-venous grafts of small caliber, and it is the general impression that thrombosis of such a graft is almost certain.

Calcium metabolism represents one of the most interesting chapters of modern investigation. Metabolic studies were carried out for the past quoter of the century and the names of Cox (1936), Korelitz (1937), McCance (1936), Thomas (1952) Hansard (1953), Nicolaysen (1953), Harrison (1955), Comar (1957), Dupuis (1957), Singer (1957), McDona1d (1957), Bekemeier (1959), Haavaldsen (1958), Palmer (1958), Linkis (1957) are permanently assorted with the advances made in this large field. The absorptive surface of the small intestine in man is estimated to exceed 10 square meters or about 8 times the area of skin of an average adult (Harkins, 1957).

No living tissue can escape the ageing process. It may express itself by alterations in structure, function, or a combination of both. The structural alterations may be visible to the naked eye, such as greying, baldness and wrinkling of the skin. Others are more subtle and may only be seen with the microscope, such as neuronal degeneration in the cerebral cortex; and still ethers cannot be seen when examined by present methods. Examples of functional alterations that may occur with age are presbyopia, presbycusis and a fall in the lung diffusing capacity (17).