Kew : Lincolnshire Psendoscorpio?is. 



205 



and thus a third view has sprung- up, namely, that the animal is 

 a passenger, using- the insect as a means of conveyance from 

 place to place, from one feeding- g-round to another. There is 

 still a further theory, that the Arachnid resorts to the insect to 

 seize parasitic Acari. This idea possesses a certain fascination; 

 but it is not supported by evidence ; and Mr. Dale has dismissed 

 it (in a letter with which he has favoured me) with the remark 

 that some flies laid hold of by Chelifers have no infesting mites. 



An early expression of the view that the Arachnid is merely 

 a passenger is contained in the already quoted communication 

 by Mr. Moore : 



Does not the Chelifer experience inconvenience, in consequence of its 

 construction, when it would be pursuing- its prey? and does it not take 

 advantag-e of the leg- which the fly so readily offers that it may ride out on 

 its hunting excursions, and, by the aid of the fly's leg's and wings, get 

 cheaply conveyed from place to place ? 



This was the view of Hagen, ~' r and it has been supported by 

 Simon and Cambridge, as well as by other observers, among 

 whom are Dr. v. Wagner and Professor Moniez.f It is 

 favoured by the fact that Diptera, with attached Pseudoscorpions, 

 are seen flying through the air, and Phalangiids hurrying over 

 the ground, the Pseudoscorpions the while appearing in a state 

 of inactivity, passively hanging generally by but one claw to 

 a limb of the conveyor. Hagen has remarked that the creatures 

 cannot obtain nourishment from the hard limbs, and that, except 

 when associating with beetles, they are always found on the 

 limbs, not on the softer body. Mr. Spicer, referring particu- 

 larly to Phalangiids, has made the same remark. Simon and 

 Cambridge have emphasized the statement that the creatures do 

 not 'appear to injure their hosts, Diptera, etc., continuing to fly 

 freely notwithstanding the presence of their comparatively 

 formidable guests. This has been remarked upon by several 

 observers, and we have seen that a small fly with five Chemes 

 attached yet flew and walked in a lively manner. Further, in 

 support of the present view, we have a direct observation bv 

 Mr. Moore, who saw a Pseudoscorpion which had been carried 

 by ;t fly from one window to another, relax its grasp and drop 

 into a crevice. One can imagine that the attachment may bo 

 a more or less accidental circumstance. The little creatures are 



* Hagen, 1867, I.e. ; 1868, I.e. 



t F. v. Wagner, I.e.; R. Moniez, 'A propos des publications recenfres 

 sur le faux parasitisme des Chernetidcs sur dilVerents Arthropodes, ' Re\ ue 

 biologique du Nord de la France, VI. (1894), pp. 47-54. 

 i'kh July 



