4t2 The Ohio Naturalist. [Vol. VI, No. 5, 



mensalism, and mentions species of Pyrophorous between which 

 and the pseudoscorpion he thinks a definite relation has been 

 established; but he admits that the species upon leaves are 

 probably the same as upon the beetles. 



As will be seen in the following topic pseudoscorpions evi- 

 dently do attack and may cause the death of flies much larger 

 than themselves. It occurs to me that this instinct for robbery 

 is the starting point that lead to the habit of holding fast to 

 insects for travel, to parasitism and to commensalism, in what- 

 ever degree these exist as a habit. It is perhaps natural for a 

 pseudoscorpion to lay hold of anything alive that comes within 

 its reach. I have distinct recollections of teasing specimens 

 with a needle or with a splinter, and that the}^ would lay hold of 

 these objects with their chelae. If, then, the attacked insect is 

 strong enough to walk or fly away, and the pseudoscorpion does 

 not kill it, he becomes a passenger; if he finds natural secretions 

 or succeeds in wounding his host, he is a parasite; if he finds 

 other insects or mites that serve his wants, he is simply a com- 

 mensalist. It is thus quite easy to understand how the three 

 conditions of travel, parasitism and commensalism may have 

 developed as a habit, if indeed the}' are not accidents, for 

 pseudoscorpions can live very well without hosts. 



Food, Cannibalism. — As I have stated before, the food of 

 pseudoscorpions is the juices of insects, mites, etc., usually 

 smaller than themselves. I have seen specimens holding some 

 smaller insect either by means of the chelae of the pedipalps or 

 by means of the chelicerae. It is generally known that they 

 feed upon psocids (corrodentia) and Hagen mentions Atropus 

 pulsatorius, the death watch, as their probable food. On the 

 other hand, I have found them {Chelijer biseriatum) associated 

 with buffalo moths and believe that they were there because the 

 moths were abundant and good feeding. 



The following observations by Bachhausen are important and 

 interesting. Thus Prof. C. Berg reports (V) that I3achhausen 

 in South America found a pseudoscorpion attached to the leg 

 of a blow-fly and hanging free. He noticed after several hours 

 that the legs of the fly became stift". The next morning the fly 

 was dead and the pseudoscorpion sucked full under some scraps 

 of paper. Bachhausen next hungered a number upon moss under 

 a glass and then gave them some small flies. The pseudoscor- 

 pions soon appeared from concealment and began to attach 

 themselves to the legs of the flies by one pedipalp. When two 

 happened to get the same fly one or the other soon let go in order 

 to get a victim of its own. The legs of the flies soon become 

 stiffened and when the flies died they dragged them into con- 

 cealment. A tabanus is reported as dying much slower than the 

 other flies. On the other hand, Muehlhausen does not find that 



