Gray 39;s Anatomy Book Price In Bangladesh
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Charles F. W. McClure. On the provisional arrangement of the embryonic lymphatic system. An arrangement by means of w-hich a centripetal lymph flow toward the venous circulation is controlled and regulated in an orderly and uniform manner, from the time lymph begins to collect in the intercellular spaces until it is forwarded to the venous circulation. Six figures 281
Ida L. Revelet. The pyramidal tract in the guinea-pig. (Cavia aperea.) Ten figures. 297 Gilbert Horrax. A study of the afferent fibers of the body wall and of the hind legs to the cerebellum of the dog by the method of degeneration. Seven figures 807
E. I. Werber. Experimental studies aiming at the control of defective and monstrous development. A survey of recorded monstrosities with special attention to the ophthalmic defects. Twenty-nine figures 529
Nearly seven years ago the wriler attempted to raise stunted albino rats with the hope that a forced retardation of growth would induce some disturbance in the firm relation which normally exists between the weight of the body and of the central nervous system. The stunted rats w^ere produced by feeding them with a minimum amount of nitrogenous food. It was found, however, that in this instance the artificial stunting did not modify the weight relation between the body and the central nervous system (Hatai '08). Although it was highly desirable to pursue this investigation further, yet on account of inconstancy and uncertainty of the outcome in raising stunted rats by the method employed, the investigation was postponed.
In 1911 Professors Osborne and Mendel pubhshed a series of remarkable papers in which the results of maintenance experiments by means of various isolated proteins were fully described. According to these investigators, albino rats about one-third grown can maintain their body weight for a considerable period without revealing any sign of nutritional or physical deterioration. This satisfactory and constant procedure for producing undersized rats renewed my interest in the problem mentioned.
The rats used were from those bred in the colonj^ at The Wistar Institute in Philadelphia and sent to the University of Wisconsin. In each case rats belonging to the same litter were divided by Dr. IMcCoUum into two lots with nearly identical body weights. The one lot was used for control and received the normal mixed ration, while the other lot, which was used for the experiment, received a specially prepared diet. As to the dietary formula, the following statements were kindly furnished by Dr. McCollum: The ration of the experimented rats which received the lipoid-free food was as follows:
At the end of the experiment these rats were shipped back to The Wistar Institute for the anatomical examination, where the writer determined the weights of the following organs: Brain and spinal cord, heart, lungs, kidneys, Uver, spleen, alimentary tract, testes and ovaries, suprarenals, thymus, thj^roid, hypophysis and eyeballs. Some of these organs were preserved for further histological examination. Besides the organs mentioned, the bones also were examined.
Although the methods employed in determining the relative amount of alteration in the various organs of the experimented rats, and also the technique for the preparation of the bones and separation of the encephalon into the four parts can be foundin my papers recently published (Hatai '13 and '14), I shall briefly restate the essential points. The encephalon was divided into four parts in the following
The bones were prepared as follows: The bones are freed from the main bulk of muscles and placed in a hot aqueous solution of 2 per cent 'gold dust washing powder.' After maceration for several hours at nearly 90C., the remaining soft parts are removed. The bones thus prepared are gently wiped with blotting paper and are weighed. . This gives the 'fresh weight.' These weighed bones are then dried at 9oC. for one week and the amount of moisture determined from the weight of the dried residue.
In order to determine the amount of modification following the experimental ration, we have employed our usual method of comparing the observed values with those found in a series of reference tables that have been compiled in this laboratory. These tables present for normal rats adequate data on all the organs and characters under consideration and in each case the graph representing the table can be expressed by a mathematical formula (Hatai '13; Hatai '14).
The only modification in procedure to which attention need be drawn is in the cases where the data from two series, 1913 and 1914, have been combined. In those cases the percentage deviation which is given in the table is the mean of the deviations for each series computed separately.
The modifications of the growth of the body in weight due to the lipoid-free ration are shown in tables 1 and 2. Table 1 refers to the growth of the albino rats belonging to the 1913 series, while table 2 refers to the growth of the 1914 series. We note in both tables that the rats fed with the mixed ration made nearly normal growth in respect to their ages (see Donaldson '06). The spring
rats in 1913 made much better growth than the autumn rats in 1914. On the other hand, the experimented rats in both series made a noticeably poor growth when contrasted with the controls. In the 1913 series we notice that the experimented rats made continuous and steady growth throughout the period of experimentation, although the total amount of growth in weight was very slight. Curiously enough the experimented rats belonging to 1914 made a still smaller growth, and indeed in some cases the final body weight is no higher than the body weight at the beginning of the experiment. This difference in growth in the two series may probably be due to the different physiological condition of the rats in these two series, combined with slight differences in the preparation of the ration. One point is clear, however: that the rats cannot continue the normal rate of growth on the lipoid-free ration in combination with the salt mixture which was used.
In table 2 we have also the data on the growth of the body of the albino rats which were fed first with the lipoid-free ration and later with the same ration to which a minute quantity of the egg-fat had been added. For convenience, these last mentioned rats will be designated simply as 'egg-fat series.'
It was found by McCollum and Davis ('13) that the rats whose body growth had ceased for a long period as the result of the lipoid-free ration, could be made to grow by the addition of a minute quantity of the extract of egg to the experimental ration. In order to see whether or not the rats thus treated would show any modifications other than those shown by the rats fed with the simple experimental ration, a small series was carried on. As will be seen from table 2, the 1914 rats given the extract of egg did not show the improvement in the growth of the body which was to be anticipated.^ Thus the growth of the body is nearly identical in both the lipoid-free series and in the egg-fat series. Why in the present experiment the egg-fat series did not show a noticeable improvement in the growth of the body is not clear. However, from the fact that the control rats belonging to the 1914 series did not make satisfactory^ growth when contrasted wdth the 1913 series, we conclude that the failure to grow was
Osborne and Mendel ('12) obtained normal growth of the rats with the ration from which the lipoid had been almost entirely removed. They carried the experiment for a considerable length of time by beginning with albino rats slightly over 30 days in age. In one series the experiment lasted for nearly 160 days. In every instance, so far as one can judge from the graphs, the body weight of the experimented rats was nearly identical with that of the control rats, while McCollum and Da\ds' rats, fed with the lipoid-free ration, did not grow at any period to the size of the controls (]McCollmii and Da\ds ' 13 ; see also present series) .
This difference in growth between the rats of Osborne and Mendel, on the one hand, and those of McCollum and Davis on the other, was undoubtedly due to the nature of the inorganic salts and some extracts still contained in the food. The Osborne and Mendel rats received the inorganic salts from protein-free milk, while those of JMcCollum and Davis received the salts which were a laboratory mixture of pm"e chem.icals. In reference to the varying effects of different salt mixtures McCollum and Davis state ('13) that
"Yoimg rats have been found to be very sensitive to variations in the character of the salt mixtures supplied, but with certain mixtures we have been able to obtain practically' normal growth for periods varying from 70 to 120 days. Beyond that time little or no increase in body weight can be induced with such ra^tions. The rats may remain in an apparent!}' good nutritional condition on those rations for man}^ weeks after growth ceases."
Although the growth rate was dissimilar in the two consecutive years, nevertheless it was found that the alterations shown by the various characters are nearly identical in the two series oi exper ments, and on account of this uniformity in the results, as well as to avoid unnecessary complication by presenting the two series of data separately, I have combined the results. Consequently, unless otherwise stated, the figures given in the tables represent the averages of the two sets of data belonging to the 1913 and the 1914 series combined.
If the hpoid-free ration is able to produce any alterations in the lipoid content of the organs, the central nervous system would naturally be expected to indicate such effects, since the central nervous system of the albino rat at about 200 days of age normally contains some 60 per cent of lipoid in the dried residue (Koch '13). This lipoid content is certainly greater in the nervous system than in any other organ (Koch '11). The weights of the central nervous systems of the experimented and of the control rats are shown in table 3 (see also page 16). As will be seen from this table, the weight of the brain with respect to the body length is generally slightly smaller in both the lipoidfree and egg-fat series. Only one exception is found in the female rats (B) fed with the lipoid-free ration in which the experimented rats show a slight over weight of 0.7 per cent. This slight increase is probably due to the abnormally small brain weight of the control rats, thus raising the relative weight of the central nervous system of the experimented rats. Indeed the nonnal brain weight of the female rats corresponding to the body length of 189 mm. should be 1.80 grams as against the observed weight of 1.73 grams, i.e., the observed weight of the control is nearly 4 per cent less than the normal brain weight. Without making any correction, however, we find on the average that the experimented rats show about 2 per cent less brain weight than the controls.
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