In the brittle-stars (ophiurians) the arm breaks off with greater ease and at any level. If the arm is simply held and squeezed, it will, in some forms, break off just proximal to where it is held. If the broken end is again held, another small piece breaks off, and in this way the arm may be autotomized, piece by piece, to its very base. Regeneration may take place from any region, but, as yet, no observations have been made on the relative rate of growth of the new arm at different levels. One of the most remarkable cases of autotomy is that in holothurians, in which the Cuvierian organs, and even the entire viscera, may be ejected when the animal is disturbed. A new digestive tract is regenerated.[74] It is known that several of the myriapods lose their legs at a definite region near the base, and that they have the power of throwing off the leg in this region if it is injured. I have often observed that the legs of _Scutigera forceps_ are thrown off if they are held or injured, and even when the animal is thrown into a killing fluid. Amongst the insects the plasmids or walking-sticks also throw off their legs at a definite joint, as described by Scudder, and more recently by Bordage, and still later by Godelmann. New legs are regenerated from the stump of the old leg, as has long been known.[75] Other insects do not have the power of throwing off their legs, and we have only a few observations that show that the legs if lost can be regenerated. It is known in the cockroach that the tarsus can regenerate if lost or if cut off, and that fewer segments are regenerated than are present in the normal animal. Newport found that the true legs of a caterpillar are regenerated during the pupa stage if they have been previously cut off. A further example of autotomy is found in the white ants, which break off their wings at the base after the nuptial flight. There exists a definite and pre-formed breaking-plane in this region. The true ants also lose their wings after the nuptial flight, but there does not seem to be a definite plane of breaking, so that the process can scarcely be called one of autotomy. These cases also differ from the other cases of autotomy in that the lost parts are not renewed.