There are alimentary as well as toxic species in every possible variety among mushrooms, some species consisting chiefly of the edible kind, others consisting of the poisonous variety. In consequence of the toxicity of mushrooms, great attention must be given to the treatment to which they are subjected when it is desired to utilize them for alimentary purposes. Thus the toxic principles of several varieties can be removed, and the mushrooms rendered edible by very simple means. Pouchet has made a very ingenious comparison between the ethereal, alcoholic, saline, and aqueous extracts of mushrooms, and bacterial cultures. The analogy is striking as to the presence of toxin, toxalbumose, and albumoses more or less toxic; it is moreover not exaggerated, since, according to the classification generally admitted, mushrooms are nothing more than the very advanced representatives of a group the more simple members of which constitute the bacteria. The same author has shown that phallin obtained from the juice of the Fly Agaric will kill a guinea-pig weighing 600 grammes in one hour. As we have already stated, it is the phalline to which the ordinary disorders which mushrooms cause are due. According to Kobert, a 1:250 000 solution of this substance causes an intense hemolysis, with all its disastrous consequences. According to Pouchet, the flesh of mushrooms must be compared with meat that has been kept for some time to become tender, and it is well known that though this "tendering" process renders the meat more digestible, it may also allow the meat to acquire noxious properties, due to the presence of toxins. Phallin is the type of those toxic albuminoids of unknown composition which exist in mushrooms, and which are comprised under the name _sapotoxins_. The intravenous injection of phallin into an animal, in the proportion of 1 part to 1 000 000 parts of body weight, causes sudden death within one minute; in the proportion of 1:5 000 000, death occurs in about three minutes; in the proportion of 1:50 000 000, death also occurs, but is greatly retarded. An injection of 0.0005 Gm. per kilo of body weight of animal causes solution of the blood corpuscles to such an extent that thirty minutes later the blood serum is strongly colored red, as well as the veins. Instead of being easily altered under the influence of an elevated temperature, as are many of the albuminoid substances, whereby their toxic power is lost, phallin may be boiled for half an hour with water without undergoing any noticeable alteration. Pellegrini has observed that the dried juice of Amanita Phalloides (Death-cup) preserves its properties for more than a year. According to a recent paper by Gillot, the symptoms of poisoning by mushrooms must be ascribed to albuminoids (phallin and albumose), alkaloids (muscarine, choline, or betaine), or to resinoids (cambogic and agaricic acids).