VASCULAR OR DUCTLESS GLANDS. Ib6 



pation, but not to normal animals, the conclusion was drawn that 

 the function of the adrenal bodies was to remove from the blood 

 some toxic material the product of muscle metabolism. Its accumu- 

 lation after extirpation gives rise to death through auto-intoxication. 



On the supposition that the adrenals might secrete and pour into 

 the blood a specific material which favorably influences general 

 metabolism, Schafer and Oliver injected hypodermically glycerin 

 and water extracts, and observed at once an increased activity of 

 the heart-beats and of the respiratory movements. The effects, how- 

 ever, were only transitory. When these extracts are injected into 

 the veins directly, there follows in a short time a cessation of the 

 auricular contraction of the heart, though the ventricular contrac- 

 tion continues with an. independent rhythm. If the vagi are cut 

 previous to the injection or if the inhibition is removed by atropin, 

 the rapidity and vigor of both auricles and ventricles are increased. 

 Whether the inhibitory influence is removed or not, there is a 

 marked increase in the blood-pressure, though it is greater in the 

 former than in the latter instance. This is attributed to a direct 

 stimulation and contraction of the muscle-fibers of the arterioles 

 themselves, and not to vaso-motor influences, as it occurs also after 

 division of the cord and destruction of the bulb. The contrac- 

 tion of the arterioles is quite general, as shown by plethysmographic 

 studies of the limbs, spleen, kidney, etc. Applied locally to the 

 mucous membranes, the adrenal extract produces contraction of the 

 blood-vessels and pallor. The skeletal muscles are affected by the 

 extract very much as they are by veratrin. The duration of a 

 single contraction is very much prolonged, especially in the phase of 

 relaxation or of decreasing energy. 



It is evident from these experiments that the adrenal bodies are 

 engaged in elaborating and pouring into the blood a specific material 

 which stimulates to increased activity the muscle-fibers of the heart 

 and arteries, and thus assists in maintaining the normal blood- 

 pressure as well as the tonicity of the skeletal muscles. The active 

 principle of this gland has been isolated by Abel and termed epine- 

 phrin. 



