208 



Kew : Lincolnshire Psendoscorpions. 



proceeding - , w"hich had been inspired by the observations of his 

 predecessors and by the ascertaining- of the fact that the 

 creatures occurred in some plenty in a manure heap in the 

 open air at Lille. It sufficed to catch flies, to cut off a wing, 

 and to place them under a bell-glass on the manure-heap ; 

 generally, in these circumstances, after a very little time, one 

 might find the Pseudoscorpions fixed by their pincers to the 

 legs of the Diptera, and Moniez's conclusion was that they 

 could not resist the desire to quit the place where they were 

 whenever the opportunity for a ride presented itself to them. 

 It is noted, however, that while Chernes nodosus, Chelifer can- 

 croides, and Roncus lubricus occurred in the manure-heap in 

 about equal numbers, this supposed desire for passive aerial 

 locomotion obtained only in the Chernes and Chelifer, the Roncus 

 never attaching itself to the flies. The attachment, whether 

 accidental or intended, obviously serves for dispersal ; but it is 

 probable that it is not a means of dispersal only, the phenomena 

 having, almost certainly, a further significance. 



It was the opinion of several of the earlier writers that the 

 fly-infesting Pseudoscorpions are parasitic. This was the view 

 of Hermann, and of Leach, * and also in more recent years of 

 Professor Leydig ;f and notwithstanding the Pseudoscorpion's 

 diminutiveness it is probable that those found attached to flies, 

 etc., are attacking the relatively gigantic creatures for the pur- 

 pose of obtaining food from them. Several recent observers 

 look upon the Pseudoscorpions under these conditions as pre- 

 daceous rather than parasitic, and justly so I think ; but the 

 distinction is not of great importance, for it merely turns upon 

 the question whether the Arachnids obtain their nourishment 

 during the life of the insect or only after its death. These 

 animals are generally stated to feed on minute insects and mites 

 and their larvse, and they are seen to seize such creatures — 

 book-lice, spring-tails, etc. — with their pincers and convey them 



* W. E. Leach, ' On the . . . Scorpionidea, with descriptions of the 

 British species of Chelifer and Obisium,' Zoolog-ical Miscellany, III. (1817), 

 PP- 4 8 -53- 



f Professor Leydig- compares the Pseudoscorpions, somewhat inaptly, 

 to Hydrachnids or water-mites during - their youth, at which time they are 

 parasitic on the legs and bodies of water-beetles and -bugs. Reference 

 might be made also to the larvae of Trombidiids or velvety land-mites 

 which we commonly see, like little red beads, adhering to harvest-men. 

 These are cases of true parasitism, the attachment of the larvae (whose 

 imagines a.re free) being essential to their existence ; and at the same time, 

 doubtless, highly useful as a means of dispersal. 



Naturalist, 



