1) This study was carried out for the histological analysis of the lesions produced by the methods of oil-wax-, etopalin-injections and electrical coagulation. 2) Etopalin tends to produce an irregular and large degenerative necrosis at the perifocal area of the lesion. This is, therefore, not desirable technique for the purpose of stereotaxic surgery to make a small, localized lesion. 3) In case of the electrical coagulation, the lesion reveals an extensive reaction of the tissues and could be hardly expected to make as large as it will be expected in size. 4) Although the operation is difficult at the time of the injection, oil-wax can produce a necrotic lesion as the result of slow tissue reaction against the expanding pressure, the mildest lesion-making process can be expected. 5) In general, Etopalin manifests the severest reaction around the contact tissue and, in contrast, the mildest can be obtained in case of the oil-wax technique.