Experimental Myopathies.- A. Pharmacotoxic Myopathies.- B. The Myopathy of Vitamin-E Deficiency.- C. Hereditary Myopathies in Animals.- The Myopathy of 2,4-Dichlorophenoxyacetic Acid (2,4-D) in the Rat.- Material, Methods and Remarks.- A. Treatment of Animals.- B. Preparation of Samples.- C. Staining Procedures and Histochemical Reactions.- Fibre Types of Normal Skeletal Muscle.- Results.- A. Effects of 2,4-D in vitro on the Histochemical Reaction for Phosphorylase in Skeletal Muscle (vt). Results and Discussion.- B. Effects of Acute Intoxication in vivo on the Glycogen Metabolism of Skeletal Muscle (avi). Histochemical Findings and Discussion.- C. Histological and Histochemical Findings in the Myopathy of Subacute Intoxication with 2,4-D (svi).- Discussion and Conclusions.- A. Muscle.- B. Myocardium.- C. Liver.- Relationship between the Myopathy of 2,4-D and Other Experimental Myopathies. Formal Pathogenetic Relationship to Muscular Dystrophy in Man.- Summary.- Zusammenfassung.- References.