*[Footnote: This positive result might suggest that the comparison of both femoral and vena-cava blood under each condition was unnecessary, and that a comparison merely of vena-cava blood before and after asphyxia would be sufficient. Positive results were indeed thus secured, but they occurred even when the adrenal glands were carefully removed and extreme asphyxia (i. e., stoppage of respiration) was induced. That the blood may contain in extreme asphyxia a substance or substances capable of causing inhibition of intestinal contractions was thus demonstrated. In one instance, after the blood was proved free from adrenin, the aorta and vena cava were tied close below the diaphragm, and the carotids were tied about midway in the neck. Extreme asphyxia was produced (lasting five minutes). Blood now taken from the heart caused marked inhibition of the beating intestinal segment. Probably, therefore, the inhibitory action of blood taken from an animal when _extremely_ asphyxiated cannot be due to adrenin alone.] That the positive result obtained in moderate asphyxia is not attributable to other agencies in the blood than adrenin is indicated by the failure of asphyxial femoral blood to cause inhibition, while vena-cava blood, taken almost simultaneously, brought about immediate relaxation of the muscle. The conclusion was drawn, therefore, that asphyxia results in increased secretion of the adrenal glands. This conclusion has been supported by Borberg and Fridericia,[151] and also by Starkenstein,[152] who found that an increase of carbon-dioxide in the blood lessens the adrenin in the adrenal medulla. And recently Czubalski[153] also has inferred, from the rise of blood pressure in asphyxia when the adrenals are intact and the absence of the rise if the adrenals are removed, that asphyxia sets free adrenin in the blood. Asphyxia, like pain and excitement, not only liberates adrenin, but, as might be inferred from that fact, also mobilizes sugar.[154] And, furthermore, Starkenstein[155] has shown that the asphyxia due to carbon-monoxide poisoning is not accompanied by increased blood sugar if the adrenal glands have been removed.