CENTIPEDES 47 



heart. In S. coleoptrata the lungs are dorsal and situated in the 

 pericardial cavity where aspiration due to systole is strongest. 

 They are bathed by blood in the ventro-lateral lacunae which are 

 connected with the pericardial cavity by pulmonary veins. Thus 

 an active mode of life, somewhat analagous to that of the wolf 

 spiders which hunt their prey in the open, is associated with 

 analagous morphological structures. At the same time the presence 

 of compound eyes in Scutigera, in contrast to the simple ocelli of 

 the other Chilopoda, may be associated with fast running after 

 flies and other insects. 



Of course the Geophilomorpha do not always burrow, particu- 

 larly the shorter-bodied species which often seek shelter under 

 stones, nor do the members of the other orders run fast all the 

 time: on the contrary they sprint only occasionally and with re- 

 luctance. Nevertheless locomotion appears to be the habit with 

 which their evolution has been chiefly associated (Manton, 1952, 

 1953). 



Centipedes always live in damp, dark and obscure places under 

 stones, fallen leaves, logs, under bark and in crevices of the soil, 

 from which, like woodlice and millipedes, they issue forth at 

 night. Sinclair (1895) claimed that in Malta Scutigera darts about 

 in the hot sunshine after its prey, but in India it is said to exhibit 

 a strong 'dislike' of daylight and hides during the daytime in dark 

 places. Its most common habitat is under matting covering the 

 floors of bungalows or on walls in dark corners and under stones 

 out of doors. In Italy too S. coleoptrata appears to be photo-nega- 

 tive (Cloudsley-Thompson, 1949). 



With the exception of their eyes which usually do not seem to be 

 of much importance, the sense organs of centipedes take the form 

 of hairs connected with nerve fibres; the animals find their prey by 

 means of these hairs which are sensitive to touch. They are also 

 very sensitive to moisture and contact stimuli. The whole subject 

 has been reviewed by Cloudsley-Thompson (1952b). According 

 to Bauer (1953) Lithobius forficatus shows a 'preference' for high 

 humidities and a ground temperature of about 12° C. 



Auerbach (1951) has found that the distribution of Bothropolys 

 multidentatus, Lithobius forficatus and Neolithobius voracior in the 

 Chicago area of North America does not follow a uniform pattern. 



