Kew : Lincolnshire Pseudoscorpio?is. 



2 I I 



The other day we put several of .both into a bottle, and often, when the 

 fly approached the Chelifer, the latter immediately extended one of its 

 claws, and seized the fly by the end of the tarsus ; with the other claw it 

 grasped either the middle of the tarsus, or the costal nervure of the wing-, 

 and then loosened the hold of each of its claws alternately till it arrived at 

 the trochanter, where it remained fixed. We added three other flies, 

 belonging to the genera Anihomyia, Sepsis, and Borborus. The first, a 

 much more active insect than the Lonchcea, was soon seized by a Chelifer. 

 It used its utmost efforts to disengage its tarsus without success ; however, 

 the Chelifer soon relaxed its hold of its own accord. When we looked at 

 the insects the following day, the Lonchcea, the Anthomyia, and the Borborus 

 were alive, and only the first had a Chelifer attached to it ; so, likewise, had 

 the Sepsis, whose death was probably occasioned by confinement not by 

 any wound. 



It is regrettable that these observations were not continued ; but 

 it is improbable that the behaviour of Chelifers in a bottle would 

 safely represent that of individuals in a state of nature. That 

 the attachment is not merely passive is indicated by the con- 

 clusions of Dr. Hess. We have already mentioned that this 

 naturalist watched a house-fly with a Chelifer on one of its legs. 

 He caught the fly at noon on 30th August and put it in a large 

 glass. The Arachnid hung by one pincer to the tibia of the left 

 front leg, the other pincer being free and ready for the fray. 

 Frequently the creature grasped the right front leg with the 

 free pincer ; but it was obliged to release it, for the fly spreading 

 out its legs liberated the right one. The two animals were kept 

 for 56 hours without their mutual relations having changed ; it 

 merely seemed that the Arachnid had moved a little higher on 

 the leg. To prevent the fly succumbing the observer frequently 

 gave it a drop of milk. It walked about freely, and when rest- 

 ing was usually engaged in attempting to detach the Chelifer, 

 using for this purpose the free front leg which it rubbed against 

 that to which its assailant was hanging. The observation was 

 accidentally terminated on the evening of 1st September, when 

 too much milk was given to the fly, the Chelifer being found 

 drowned on the following morning. It is unfortunate that the 

 observation thus remained incomplete — the leg did not appear 

 to have, been injured— but Dr. Hess tells us that in view of the 

 proceedings of the Chelifer, and the obstinacy with which it 

 maintained its position, no doubt remained in his mind that its 

 intention was to attack and feed upon the fly. In all probability 

 the creatures sometimes realise that their chances of causing 

 the insect's death are hopeless ; and we have seen that they 

 occasionally detach themselves. That they may be successful, 

 however, seems clear from the observations of Mr. Stainton 



1901 July 2. 



