=Poisonous Plants.=--Statistics in regard to poisonous plants are lacking on account of a general ignorance of the subject, and it is therefore impossible to form even an approximate estimate of the damage done by them. Besides the criminal uses that may be made of them, there are some other problems connected with them that are of general public interest. The common law of England holds those who possess and cultivate such plants responsible for damages accruing from them; and a New York court has awarded damages in a case of injury from poison ivy growing in a cemetery. In order to obtain information on the subject, the botanical division of the Department of Agriculture arranged to receive notices through the clipping bureaus of the cases of poisoning recorded in the newspapers. Thus through the persons named in the articles or through the local postmaster it was put in correspondence with the physician in the case, who furnished the authentic facts. A large number of correct and valuable data were thus secured. It is proved by these facts that all poisonous plants are not equally injurious to all persons nor to all forms of life. Thus poison ivy has no apparent external effect upon animals, and a few of them eat its leaves with impunity; and it acts upon the skin of the majority of persons with varying intensity--on some hardly at all, while others are extremely sensitive to it. A similar variability is found in the effects of poisonous plants taken internally. In some cases often regarded as of that kind, death is attributable not to any poison which the plant contains, but to immoderate or incautious eating, or to mechanical injury such as is produced in horses by the hairs of crimson clover, or to the effect of parasitic growths, such as ergot on rye. Excluding all which operate in these ways, there are, however, a large number of really poisonous plants, the properties of which are comparatively unknown. It is concerning these that information has been sought by the botanical division. Its report contains descriptions of about forty plants, with figures, belonging to seventeen families.