¹ E. Benveniste. Diogenes I, p. I. I refer readers to his description of the ‘dance', but take the opportunity of drawing attention to what would appear to be a slight error. On p. 2 in the fourth and fifth lines from the bottom it is stated that the bee ‘flies' in the course of its dance in the hive. In fact it walks or runs on the comb. I would also add that von Frisch has recently given an excellent account of his recent work in Structure et physiologie des sociétés animales, published by the Centre National de la Recherche Scientifique, Paris.

² J. B. S. Haldane and H. Spurway. ‘A Statistical Analysis of Communication in Apis mellifera, and a Comparison with Communication in Other Animals.' In the press.

³ Edward A. Armstrong, Bird Display and Behaviour, London: Lindsay Drummond, 1947.

⁴ N. Tinbergen, ‘Derived' Activities, Their Causation, Biological Significance, Origin, and Emancipation during Evolution'. Quarterly Review of Biology, 27, pp. 1-32, 1952.

⁵ Robert Mertens gives a full account of such phenomena in ‘Die Warn- und Droh- Reak tionen der Reptilien' (Abhandlung 471 der Senckenbergischen Naturforschenden Gesellschaft, 1946). Tail-swinging and tongue movements are common. Lizards of the genus Phrynosoma squirt blood from beneath their lower eyelids, while other reptiles bleed from other parts of the head. Of the snake Tropidophis semicinctus Mertens writes, ‘Während des Blutens verloren die Augen ihre unansehnliche dunkle Färbung und wurden rubinrot.' Virgil's suffecti san guine is thus probably based on observation, though the habit is commoner in American than in Old-world reptiles. Milton's lines may be an echo from Canto I of Marini's La Strage degl' Innocenti.

⁶ N. Tinbergen, Social Behaviour in Animals, London: Methuen, 1953.

⁷ A. N. Promptov and E. V. Lukina, ‘Conditioned-Reflectory Differentiation of Calls in Passeres and its Biological Value', C. R. (Doklady) Ac. Sci. U.R.S.S. 46, pp. 382-384, 1945.

⁸ This is a development of Promptov and Lukina's statement ‘The existence of adequate con ditioned reflectory connexions between a definite sound stimulus (call) and the motor reac tion permits of a rapid conveyance of a given physiological state from one individual to many others who in turn "broadcast" it to their neighbours'. The notion that the utterance of a cry, usually made before a certain activity, whether this connexion is innate or learned, generates the emotion or physiological state leading up to this activity, does not differ greatly from the Lange-James theory of emotion.

⁹ Martin Lindauer, ‘Bienentänze in der Schwarmtraube', Naturwissenschaften 22, pp. 509-513, 1951.

¹⁰ F. Engels, ‘The Part Played by Labour in the Transition from Ape to Man', English trans lation in Dialectics of Nature, London: Lawrence and Wishart, 1940.

¹¹ The quotations from Dante follow the Testo critico della Società dantesca italiana.