M. NICOLLE holds such a high place among those who have made contributions of real importance to our knowledge of parasites that it seems a pity he should put out this disorderly summary of some of the researches of himself and his collaborators. It reads like a bundle of notes that a man might make to define the current position of his investigations, and to settle which piece of work he should take up next. With trivial exceptions M. Nicolle reviews no facts but those of his-own discovery, and it is impossible to distinguish between conclusions and hypotheses. He points out, for example, the similarity of symptoms and anatomical lesions produced by various toxins of different origins, and the diversity and specificity of the antibodies which result from their introduction into the animal economy. He therefore concludes that toxins consist of two parts, one poisonous and not an antigen, the other inactive and an antigen. This is no more than a possibly fruitful hypothesis on which to base further experimentation. Those who know the subject well might run through the book with advantage; others had better leave it alone.
Toxines et Antitoxines.
By. Pp. viii + 123.(Paris: Masson et Cie, 1919.) Price 5 francs net.