78 SCORPIONS 



From a detailed histological study of the pectines, Schroder con- 

 cluded that they were chemotactic organs and had a double func- 

 tion as receptors for taste and smell and were perhaps also used 

 during mating as a stimulatory organ {Wollustorgane) in the recog- 

 nition of the sexes. With still more imagination, Ubisch attributed 

 to them an auxiliary role in respiration. She suggested that with 

 their complex musculature, the pectines could be used as fans to 

 blow fresh air across the lung-books while the scorpion was in its 

 stuffy retreat, and that they served to ventilate the lung-books 

 when the animal rested on the ground by lifting the pre-abdomen 

 and thus permitting air to pass freely beneath the body. 



On the other hand, Schultze (1927) observed in the case of the 

 large Philippine forest scorpion Palamnaeus longimanus that while 

 giving birth to young the pectines of the mother scorpion 'were 

 carried in a vertical position pointing downwards, seemingly to 

 serve as holders or bracers'. 



Finally, Lawrence (1953)* wrote: 'The pectines of scorpions have 

 been interpreted either as tactile or stimulatory organs during 

 courtship, or as organs of smell. The latter seems to be the more 

 likely explanation except that their position is peculiar in the arthro- 

 poda, where these organs are generally located on the antennae or 

 legs'. After reviewing some of the functions that have been attribu- 

 ted to the pectines, Millot and Vachon {in Grasse, 1949)* con- 

 cluded with justifiable caution: 'Toutes ces hypotheses ne font que 

 masquer notre complete ignorance.' 



As a result of experiments carried out on Buthus occitanuSy 

 Androctonus australis and Euscorpius germanus, in which it was 

 found that the response of the scorpions to a vibrating tuning fork 

 decreased markedly after the pectines had been painted over, it has 

 recently been suggested that the function of these organs lies in 

 the perception of ground vibrations (Cloudsley-Thompson, 1955b). 

 Probably they are used more as a warning of danger than in the 

 detection of prey. 



It is a well-known fact that a number of the larger species such 

 as the greenish-black Palamnaeus swammerdami of southern India 

 will frequently emit audible sounds under the stimulus of fear or 

 of anger. The sound is said to be almost as loud as, and very similar 

 to that made by briskly and continuously drawing the tip of the 



