[ 349] TEMPERATURE ADAPTIVE BEHAVIOUR IN THE SCORPION, OPISTHOPHTHALMUS

In discussing the possible functions of the pectines of the scorpion, von Ubisch (1922) suggests that they serve 'um den Stigmen frische Luft zuzufuhren ' by their fanning movements or, alternatively, they prop up the mesosoma so that fresh air can reach the stigmata. Both of these suggestions imply that under conditions of respiratory stress a scorpion will lift its mesosoma clear of the ground so that the book-lungs have free access to air. Although von Ubisch did not apparently observe such behaviour, the recent report of 'abdominal elevation ' in the Australian scorpion, Urodacus abruptus Poc. (Southcott, 1955) lends colour to such an hypo-thesis, although work on the functions of the pectines makes it seem very improbable that they actually serve as 'respiratory fans'. Southcott gives an illustration of a female of U. abruptus in the attitude typical of 'abdominal elevating behaviour', and from a comparison of this with some of the stances observed in various South African scorpions it becomes clear that such behaviour occurs also in the latter. Opisthophthalmus latimanus Koch, O. nitidiceps Poc, O. austerus Karsch., Para-buthus planicauda Poc. and Uroplectes trianguUfer Thor. all show the pattern t