H. C. LONG. SURBITON, _October_, 1916. CONTENTS CHAP. PAGE I. INTRODUCTION 1 What is a Poisonous Plant? Harm done by Poisonous Plants. Circumstances in which Poisoning occurs. Effect of Soil, Climate and Cultivation on the Toxic Properties of Plants. Variation in the Poisonous Parts of Plants. Eradication of Poisonous Plants. Treatment of Poisoned Animals. Tests with Suspected Plants. Legal Aspect of Plant Poisoning. The Toxic Principles of Plants. II. RANUNCULACEÆ. PAPAVERACEÆ. CRUCIFERÆ. CARYOPHYLLACEÆ. HYPERICINEÆ. GERANIACEÆ 9 III. CELASTRACEÆ. RHAMNACEÆ. PAPILIONACEÆ. ROSACEÆ. CUCURBITACEÆ. UMBELLIFERÆ 24 IV. ARALIACEÆ. CAPRIFOLIACEÆ. COMPOSITÆ. ERICACEÆ. PRIMULACEÆ. OLEACEÆ. CONVOLVULACEÆ. SOLANACEÆ 43 V. SCROPHULARINEÆ. POLYGONACEÆ. THYMELACEÆ. EUPHORBIACEÆ. AMENTACEÆ. CONIFERÆ. AROIDEÆ 61 VI. DIOSCORIDEÆ. LILIACEÆ. GRAMINEÆ. EQUISETACEÆ. FILICES. FUNGI 78 VII. PLANTS SUSPECTED OF BEING POISONOUS 92 VIII. THE EFFECTS OF PLANTS ON MILK. PLANTS WHICH CAUSE MECHANICAL INJURY 99 IX. CLASSIFICATION OF POISONS 103 BIBLIOGRAPHY 106 INDEX 114 Photograph of three varieties of _Phaseolus_ beans, of Castor Oil Beans, Indian Peas, and Ergot _Frontispiece_ CHAPTER I INTRODUCTION.