The growth of the animal body, or any of its constituent organs and tissues is observable to all as a gradual increase in size. It is possible to study growth at several levels. It may be measured at the level of the organism proper; at the level of the tissues or organs; at the level of the cells and now, by chemical methods, even at the level of molecules. However, a growth is analyzed into its constituent parts, the problems of expressing the process have become manifold. Indeed, as Weiss (1949) staged, “It (growth) is not even a scientific term with defined and constant meaning, but a popular label that varies with accidental traditions, predilections, and purposes of the individual or school using it.”

Since the time of its discovery (Fontana, 1781; cited by Montgomery, 1898), the nucleolus has been the subject of numerous investigations. The morphology and chemistry of nucleoli, as well as the origin of nucleolar material, have been ably reviewed by Vincent (1955) and by Stich (1956). Although the literature is very extensive, little quantitative data is available regarding the absolute numbers and sizes of nucleoli. Historically, Lebert (1851; cited by Hoffman, 1953) was the first to attempt an assessment of nuclear and nucleolar diameters in animal cells. His measurements of cancer cell nuclei and nucleoli are, however, of little consequence as quantitative information.

In the field of Physical Education, "physical fitness" has a definite meaning though the term has so far defied accurate physiological definition. Since "fitness", in the light of present day definitions is generally considered to result from "physical training", most scientific investigations in this field has been directed towards measuring the effects of "training" on cardiovascular and respiratory parameters or towards comparing these parameters in the trained and untrained subjects. Some of the parameters, in particular those which are easily measured such as pulse rate, ventilation and oxygen uptake, have been well studied and the changes which occur on exercise and the way training effects these changes have been well documented.

The main purpose of this investigation was to determine whether a difference between the pancreatic duct system in male and female may explain the higher incidence of pancreatitis in the female and, on the contrary, the higher frequency of pancreatic tumours in the male. Paxten and Payne ('48); Morse and Achs (149) and Edlund ('50) have statistically shown that pancreatitis is seen two to three times more often in the female than in the male, while carcinoma of the pancreas is twice as common in males as in females, (Willis, ‘48; Anderson, ‘51). Furthermore, this study will provide a precise account of the basic anatomy of the pancreatic duct pattern. The pancreatic duct system of twenty foetuses, twenty infants and one hundred and forty four adults, was therefore examined by eosin injection, radiological and dissection techniques.

Mechanical stresses in organs and tissues are taken up mainly by fibrous extracellular connective tissue components, namely collagenous, reticular, and elastic fibers. However, same tissues are insufficiently supported in this way and have developed a supporting apparatus of their own, which is quite different from that provided by connective tissue. One component of this supporting apparatus is a system of intracellular fibrils. Well known examples of such intracellular fibrillar systems are the tonofibrils of epidermal cells and the terminal web of intestinal epithelial cells. These intracellular fibrillar systems are often intimately associated with intercellular attachment sites, namely desmosomes and terminal bars.

An Antigen is a substance, which, when introduced parenterally into an animal, induces the production of a specific serum globulin which has the unique property of combining specifically with the antigen. Most proteins are antigenic, but antigenicity is not confined only to proteins. Thus, conjugated proteins (Felton, 1934), polysaccharides (Avery, et al 1931), and lipids (Boivin et al, 1935) have shown to be antigenic. One can not state unequivocally what physical and chemical characteristics make a substance antigenic.

The microscopic structure of the small intestine of the rat follows the structural plan of that in other mammals. It has four main layers: serosa, muscular layer, submucosa and mucosa. The main components of the mucosa are the crypts of Lieberkuhn embedded in lamina propria and the finger-like projections, the villi with a lamina propria core and with a single covering layer of epithelial cells. The cells of the crypts of Lieberkuhn ('crypt epithelium') and the cells covering the villi ('villus epithelium') are of common embryological origin and of similar morphological characteristics, thus together they are called the intestinal epithelium (Paneth, 1888; Heidenhain, 1888). The intestinal epithelium of the mucosa, which plays an important role in digestion, is renewed continuously from the proliferative activity of the crypt epithelial cells.

The currently accepted ideas on the formation of the pancreas revolve around the belief the organ developes from two separate primordial which arise from distinctly different points along the longitudinally disposed wall of the foregut. Accordingly it has been contended that certain portions of the duct system in the adult gland are associated with one or the other primordium developmentally. Many variations in the patterns displayed by the intraparenchymal duct system have been described but little attention has been given as to how such a wide range of variation might be explained from a developmental point of view. By studying the spatial arrangements of the ducts in a representative number of specimens, enabled by careful preparation of precise stereoradiographic pancreatograms in each instance, the reflections these arrangements and their variants could be considered to throw upon the formation of the gland during its development are critically examined.

The necessity for precise and descriptive cardiac anatomy has become most imperative in view of advances in heart surgery. Until recently, emphasis has been directed toward the study of intra-cardiac anatomy only by select theoretical anatomists with no direct practical application to functional medicine; however, with the advent of the heart-lung machines, improved techniques for extra-corporeal circulation and hypothermia, more and more cardiac surgical techniques are being developed and perfected. The potentialities for an increased number of intra-cardiac surgical procedures naturally follows the perfection of the mechanical devises making such surgery possible.

The term "axona migration" may be given two meanings: a narrow and a broad one. The term in its narrow sense refers only to the hypothesis that a certain material present in the axon would migrate in a peripheral direction, a good example of this concept is provided by the neurosecretion theory in which neurosecretory granules are believed to migrate distally along the axon. The broad meaning, as outlined in Weiss's concept implies proximodistal movement of the axon as a whole and therefore correspnds to a "continuous growth of the axon." According to Weiss and Hiscoe (1948), this theory is summarized as follow: "Growth, in the sense of production of new protoplasm, occurs solely at the base of the fiber in the nucleated part of the cell body. the column of axoplasm is maintained in constant proximodistal motion. Growth and centrifugal convection of axoplasm are not confined to the period of active elongation and enlarement, but continue in the mature fiber which has reached a stationary condition. The perpetual growth of the neurone presumably serves to replace kutabolized protoplasmic systems, especially proteins, which cannot be synthesized in the peripheral cytoplasm." [...]