Lower Animals. 
279 
1884.] 
a muscular movement of a reflex character, induced by irri- 
tation of the sensient nerves of the tail. The phenomenon 
differs, however, in one respeCt, in the crab and in the blind- 
worm. In the former the fracture is effected at one only 
point, whilst in the blind-worm several pieces of the tail 
may be thrown off in succession. 
The portions thus amputated by the animal retained for 
more than ten minutes an alternating lateral movement to 
the left and the right. These movements ceased at once if 
the spinal cord was destroyed, but otherwise became gra- 
dually fainter and ceased, but reappeared on irritation. 
Microscopic examination showed that the fraCture took place 
in the level of the sinews, and never in the contractile sub- 
stance of the fibres. 
Experiments with a lizard, several spiders, and inseCts 
convinced M. Fredericq that these animals display the phe- 
nomenon of an aCtive self-mutilation. 
[Without questioning the accuracy of the observations of 
M. Fredericq, and of the conclusions based upon them, we 
must be permitted to doubt whether the latter are applicable 
to all cases of self-mutilation. On two occasions we have 
seen a Tipula oleracea fall into a cobweb, and escape with 
the loss of a leg. Here there was no irritation applied to 
the foot, and the leg yielded merely to “ a long pull, and a 
strong pull, and a pull altogether,” just in time. The case 
of the Epeira is open to doubt. The observer thought that 
she was intentionally amputating the leg lest the venom 
should extend up to the body ; but it is possible that the 
irritation of the bite of the Tegenaria may have led to a 
reflex fraCture. It is said that lobster-fishers dread a thunder- 
storm, as the captive lobsters sometimes shed their claws. 
Is this assertion capable of being verified ? If so it does not 
agree with M. Fredericq’s observations, since the aCtion, 
though doubtless reflex, is not due to any irritation of the 
limb below the point of fraCture.] 
