. Studies in general physiology. Physiology; Phototropism; Geotropism; Reproduction; Irritability; Regeneration (Biology). FIR. 136 no secretion occurred at the anterior end (in the region SS); a secretion occurred instead close behind S in the region ab, that is to say, in the regions directed toward the anode of the animal, which still possessed a spinal cord. The destruction of the anterior portion of the spinal cord SS had no effect upon the secre- tion when the current was sent in a homodromic direction. In both cases J» secretion occurred in the region cd (Fig. 137). I have often repeate
. Studies in general physiology. Physiology; Phototropism; Geotropism; Reproduction; Irritability; Regeneration (Biology). FIR. 136 no secretion occurred at the anterior end (in the region SS); a secretion occurred instead close behind S in the region ab, that is to say, in the regions directed toward the anode of the animal, which still possessed a spinal cord. The destruction of the anterior portion of the spinal cord SS had no effect upon the secre- tion when the current was sent in a homodromic direction. In both cases J» secretion occurred in the region cd (Fig. 137). I have often repeated this remarkable experiment, always with the same result. It might be thought that the destruction of the spinal cord had an inhibiting effect upon the secretion of those glands of the skin which are connected with the de- stroyed portion of the spinal cord, and I was myself inclined to believe this. When I subjected pieces of Amblystomae, in which the spinal cord had been destroyed either entirely or in part, to a transverse current, I found to my surprise that secretion still occurred at the anode, it mattered not whether the spinal cord was destroyed or not. In view of this fact only one other assumption remains, namely, that two sources exist for the stimulation of the glands of the skin through the gal- vanic current. One of these is stimulation of the central nervous system; the second, the direct stimulation of peripheral organs, either the peripheral nerve fibers which go to the glands of the skin, or the nerve end- ings in the skin, or perhaps the glands themselves. In dealing with a current running longitudinally we have to do with only the first source, and polar stimulation of the central nervous system occurs at the anode. In the case of a transverse current we have to deal, in addition to this, or. FIG. 137 Digitized by Microsoft®. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - colora
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