PHYSIOLOGY. 



635 



or less anatomically distinct. 3. That the cen- 

 ters for the lower part of the face and tongue 

 are situated in the inferior extremity of the 

 ascending frontal convolution, and that in most 

 persons the posterior part of the inferior fron- 

 tal convolution, and its junction with the as- 

 cending frontal in the left hemisphere, are 

 specially connected with the faculty of speech. 

 4. That the centers for the arm are situated in 

 the middle portion of both ascending convolu- 

 tions, and that they extend into the upper third 

 of these convolutions to a distance which is at 

 present uncertain. 5. That the centers for the 

 leg occupy the upper extremities of the two 

 ascending convolutions and the parts continu- 

 es with them on the internal aspect of the 

 hemispheres. 



W. Kiihne, having made observations of the 

 motor-nerve endings on a considerable number 

 of vertebrates, has given descriptions of the 

 manifold forms of the terminal ramifications 

 of the axis-cylinder in various species. By a 

 3ial method of treatment he brings the axial- 

 tree (Axialbaum), as he styles it, into a visible 

 state while preserving its natural form, when 

 the motor-plates can be seen with surprising 

 distinctness. He has also devised a new method 

 for isolating the end-plates, when the real ar- 

 borization is revealed, quite different from the 

 apparent arborization before isolation. The 

 ramifications are composed of the axis-cylin- 

 der, and a sheath of substance which Kuhne 

 calls the stroma, separating the axis-cylinder 

 rom the fundamental substance of the motor- 

 plate. The terminal ramifications in Rana 

 (the frog) are formed, according to Trinchese, 

 of little disks, placed at more or less regular 

 distances from one another, and separated by 

 a homogeneous intermediate substance. From 

 these ramifications on the side toward the 

 muscles, run out numerous very fine filaments. 

 The " longitudinal striae " of the muscle have 

 a similar structure to that of the axis-cylinder, 

 being formed of disks united by clear inter- 

 mediate substance; and the disks are united 

 by lateral filaments with one another. 



Beaunis has described the results of obser- 

 vation-* made upon himself with regard to the 

 time that elapses between the stimulation of 

 the sense of smell and the giving of the signal 

 indicating the perception of the sensation. He 

 finds that stimuli like ammonia and acetic acid, 

 which excite not merely fibers of the gustatory 

 nerve, but also nerves of common sensation, 

 have a shorter reaction time than stimuli which 

 act only or mainly on the nerve-fibers concerned 

 with the sense of smell proper. In the cases 

 of camphor, asatetida, ammonium _ sulphide, 

 chloroform, carbon disulphide, valerian, mint, 

 and carbolic acid, the reaction time increases 

 in the order of the names from '50 to -67 of a 

 second. The moment of olfactory perception 

 of musk could not be determined. The time 

 of reaction appears to be longer in the case of 

 this sense than in those of touch, sight, or 

 hearing. Results in the main concordant 



with these have been reached by Buccola of 

 Turin. 



Digestion. Herzen, investigating the func- 

 tions of the spleen, has brought forward a the- 

 ory by which the apparently contradictory con- 

 clusions of Schiff and Ileidenhain may be rec- 

 onciled. Schiff was led to believe that after 

 removal of the spleen, the pancreatic secretion 

 lost its power of digesting proteids, and con- 

 cluded that, though the spleen did not itself 

 make the proteolytic ferment, it furnished to 

 the blood something essential to the formation 

 of it in the pancreas. Ileidenhain showed, in 

 1875, that a substance (zymogen) capable of 

 yielding proteolytic ferment accumulated in 

 the pancreas quite independently of the pres- 

 ence or ^absence of the spleen. Herzen has 

 found that, after removal of the spleen, the pan- 

 creas may still heap up zymogen (trypsogeri), 

 but that this is not under such circumstances 

 transformed into a proteolytic ferment (t/ryp- 

 sin\ as it is normally when the spleen is pres- 

 ent, and in physiological activity. Hence, after 

 splenotomy, or in cases of serious splenetic dis- 

 ease, the digestion of albuminous substances is 

 greatly impaired. 



Winogradow has described the results of 

 spleen extirpation as manifested in the blood, 

 lymphatic glands, and bone-marrow of dogs, 

 several of which were kept alive, in good 

 health, for more than two years after the sple- 

 notomy. The number of red corpuscles in a 

 cubic metre of blood always falls in a short 

 time after the operation till, in from 150 to 200 

 days, it is less than half the normal number. 

 After twelve months there begins a gradually 

 increasing proportion of abnormally small red 

 corpuscles, while those of exceptionally large 

 size, some of which are always found in nor- 

 mal dog's blood, entirely disappear. The white 

 corpuscles show no morphological change; 

 their absolute number is sometimes increased, 

 sometimes diminished. In one case, after 132 

 days, most of the lymphatic glands were found 

 enlarged, softer than the normal, and red on 

 section, especially in the cortical layer, the 

 color depending mainly on red blood-corpus- 

 cles which were abundant in the lymph chan- 

 nels of the gland, but being partly due to de- 

 posits of brownish-red pigment, the detritw of 

 broken-down corpuscles. The marrow in the 

 central cavity of nearly all the long bones 

 was red-colored, the coloration being due to 

 red corpuscles lying outside the blood-vessels 

 in the spaces of the proper marrow-tissues. 

 Later, similar but less marked divergences 

 from the normal structure were found in both 

 the lymphatic glands and the bone-marrow. 

 Transfusion of the blood of a dog which had 

 undergone splenotomy produced similar ef- 

 fects in the lymph-glands and bone-marrow of 

 another dog. 



Messrs. R. H. Chittenden and J. 8. Ely have 

 made a series of experiments to ascertain the 

 amount of alkali present in normal mixed human 

 saliva, and whether the alkalinity is subject to 



