PHYSIOLOGY. 



647 



Alps, that the red coloring matters of green plants 

 are probably of the nature of glucosides, and are in 

 most cases unions of tannin compounds with sugar. 

 The chief factors in their production are sunshine, 

 which, on the one hand, augments assimilation and 

 the production of sugar, and, on the other hand, 

 accelerates the chemical process leading to the 

 formation of the pigment, and the low tempera- 

 ture, which prevents the conversion of the sugar 

 into starch. In other words, the red autumnal 

 tints are in great measure the direct results of the 

 autumnal climatic conditions. It is possible in 

 many plants to produce red autumnal tints at any 

 time of the year by feeding with glucose. Gener- 

 ally speaking, this artificial production of red cell 

 sap is possible only when the natural reddening of 

 the leaf has its seat in the mesophyll cells. In 

 cases where the coloration is in the epidermis ex- 

 periments with glucose are unsuccessful. 



As the result of the examination of numerous 

 tumors, M. F. J. Bosc has found that the abnormal 

 formations foreign to the tissues can be grouped 

 under five morphological types microbial forms, 

 granulations, cellular forms of very variable origin, 

 encysted forms, and sarcotic forms. All these forms 

 exist in epithelia, carcinoma, and sarcoma, but sar- 

 coma contains especially the microbial forms and 

 the granulations. 



Prof. Kiittner, of Tubingen, found from experi- 

 ments with Rontgen rays, at the Constantinople 

 Hospital, that splinters of bullets and of bone which 

 had penetrated into the soft parts of the body could 

 not be distinguished from one another. It also ap- 

 peared that the opinion that deep-lying pus could 

 be located was erroneous. Injuries to the central 

 nervous system, the spinal cord, and the peripheral 

 nerves were solely ascertainable by the aid of the 

 Rontgen rays ; it was impossible to do this before. 

 It could, further, be seen whether a bone was totally 

 or only partially severed. It was recommended that 

 photographs be taken for shot, wounds in the ex- 

 tremities. The author concluded that the Rontgen 

 rays are of great importance for medical aid in 

 war, but only for fixed hospitals, such as reserve 

 hospitals and those installed in fort reserves, while 

 for moving field hospitals their application is very 

 limited. 



For a long series of observations upon the surface 

 and the deep temperature of healthy men M. S. 

 Pembrey and B. A. Nicol applied their tests to the 

 urine and the rectum. The average of 343 obser- 

 vations upon the temperature of the rectum was 

 98.24 F., and that of 377 determinations of the 

 temperature of the urine was 98.64 F. for a day of 

 twenty-four hours. The average for the time of 

 activity (7 A.M. to 11 P.M.) was 98.58 F. for the 

 rectum, and 99.12 F. for the urine; while for the 

 period of rest it was, respectively, 97.42 F. and 

 97.67 F. The maxima of the averages were 99.25 

 F. and 99.58 F. ; the minima, 97.03 F. and 97.25 F. 

 The times of the maxima were about 6 P.M. and be- 

 tween 4 and 5 P.M.: the times of the minima were 

 about 2 A. M. and between 4 and 5 A. M. The maxima 

 of all the observations, except those taken immedi- 

 ately after considerable exercise, were 100.0 F. and 

 100.1 F.; the minima, 96.8 F. and 96.9 F. Mus- 

 cular exercise produced a marked rise, even as high 

 as 101 F.. in the temperature of the rectum and 

 urine. This might be accompanied by only a slight 

 rise or fall in the temperature of the mouth. The 

 temperature of the mouth was found not to be an 

 exact measure of the deep temperature of the body. 

 It is unreliable after exercise or in cold weather, 

 owing to the cooling of the mouth. In some cases 

 the buccal temperature may be from 3 to 4 F. be- 

 low the temperature of the rectum or urine. Mon- 

 tal work has apparently little influence upon the 



temperature : it is generally accompanied by a fall 

 in temperature, owing to the concomitant decrease 

 in muscular activity. The effect of rest and sleep 

 is to produce a steady fall in the temperature, and 

 is the most important factor in producing the fall 

 in the curve of daily temperature. The effect of 

 food is to raise slightly (from 0.3 to 0,7 F.) the 

 temperature of the rectum and urine, and, in the 

 case of the evening meal, somewhat to delay the 

 fall of temperature at that time. The mouth shows 

 a relatively greater rise, owing to the increase in 

 the vascularity and muscular and glandular ac- 

 tivity of the tissues bounding the mouth. After a 

 hot meal the temperature of the mouth is often 

 above that of the rectum. The temperature of the 

 rectum shows an average excess of 0.48 F. over that 

 of the urine, and of LIT" F. over that of the mouth. 

 The average temperature of the urine is 0.82 above 

 that of the mouth. The relative values, however, 

 vary under different conditions. The surface tem- 



Eerature of the skin in the exposed parts of the 

 ody is liable to considerable variations, but that 

 of the parts habitually covered by clothes is fairly 

 constant. A simple flat-bulb mercurial thermom- 

 eter readily gives results which compare favorably 

 with those given by thermo-electric methods of de- 

 termining the temperature of the skin. 



The formation of enamel has been studied by 

 Charles S. Tomes in the teeth of the Elasmobranch 

 fishes, and he concludes that just as the teeth in 

 that order present the simplest known form of 

 tooth development, so they also present the first 

 introduction of enamel as a separate tissue. In 

 the first introduction it was a joint product, made 

 under circumstances which almost precluded the 

 formation of an outer layer upon the teeth ; but 

 in the further specialization of teeth in reptiles 

 and mammals the tooth germs sink more deeply 

 into the submucous tissue, and are protected for a 

 much longer time. The enamel organs become 

 more specialized, and finally take upon themselves 

 the entire work of enamel building, manufacturing 

 both the organic matrix and furnishing it with 

 lime salts, as unquestionably happens in mammals. 

 If these conclusions be correct, it would be quite jus- 

 tifiable to call the formation in these fishes enamel, 

 even though the dentine pupila has had a share in 

 its production. 



The hepatic organ is found by M. A. Dastre. when- 

 ever it is present, to be always distinguished from 

 the other tissues by the increased amount of iron it 

 contains. Thus in the Crustacea the liver is rich in 

 iron, containing four times as much as muscle, 

 while the blood and ovary contain practically none. 

 In cephalopod rnollusks the hepato-pancreas con- 

 tains, weight for weight, twenty-five times as much 

 iron as any of the tissues; in Lamellibranchs the 

 ratio is about 5 to 1, anil in Gasteropods the same. 

 The presence of this iron is independent of the 

 metal in the blood. Thus, when copper is present 

 in the blood as luemacyanin, iron only is present 

 in the hepatic tissue. 



It has been shown by M. Raphael Dubois that 

 the active agent in the production of light by 

 animals and plants is a substance possessing the 

 characteristics of the zymoses, which has been 

 named, from that fact, luciferose. The light is 

 not the result of combustion, or even of direct 

 oxidation. The fixation of oxygen was shown by 

 subsequent researches to be necessary, but it is 

 effected indirectly, or through the intervention of 

 luciferose, which behaves in this relation liko an 

 oxidizing ferment. The luminous organs of glow- 

 worms and of the eggs contained in the ovaries of 

 the female give a blue color with tincture of guaia- 

 cum. The blood of the glowworm and of some 

 other insects give the same reaction ; but the au- 



