appearance and cloacal pulsations persist unchanged in specimens which do not become moribund.

In groups of specimens collected at the same time and which received the same treatment, it was found that some would survive in excellent condition after auto-evisceration but that a large percentage would die. In some it occurred even after stages of regeneration had well commenced. From Table I it can be seen that S. mollis kept in aquarium tanks with non-running sea-water all died. Of 45 specimens, 38 died without any signs of regeneration and seven were killed for study as soon as they showed a sustained contraction and any sloughing of the body wall. One survived for 15 days before reaching this state. At Dunedin no specimens could be found close to low-tide level along the coast. All specimens studied there were obtained from trawlings at about 40 metres. Many of these were partly crushed by the weight of material in the trawl. Sixty-two such specimens had autotomised by the time they could be transferred to a container of fresh sea-water. None of these survived more than 20 days at Portobello Marine Aquarium, where they were kept in tanks supplied by running sea-water. Those collected near the end of a trawling were uncrushed and autotomy in these did not occur until treatment in the laboratory. Of 28 such specimens, 13 died within 20 days, but eight survived from 20–50 days and showed definite evidence that regeneration had commenced before they became moribund. Seven were in excellent condition when killed for study of regenerated tissues. Those collected by hand from near low-tide level in the Cook Strait area and kept in crates at Te Aro baths showed a similar high mortality rate up till 20 days after autotomy. Of 122 specimens, 65 died in less than 20 days, and 21 were becoming moribund when killed for study. The remaining 26 were in excellent condition when killed for study. The preceding specimens were treated before the arrival of Domantay's (1930) paper from U.S.A. and autotomy in all, except those crushed during trawling, was induced by standing them in a small volume of sea-water until autotomy occurred.

Those in which autotomy was induced by the injection of distilled water showed a much higher survival rate than any treated by other methods. Of 52 specimens only 3 died within 20 days, and the 12 which eventually became moribund survived 30–80 days after autotomy. The remaining 37 were all in excellent condition when killed for study at intervals up to 145 days after autotomy. Some specimens not yet examined are still active after longer than this time.

Although autotomy in S. mollis can be induced by a variety of stimuli, survival of the animal after the process depends greatly on the method used and the rapid transference of autotomised specimens to fresh circulating sea-water. The difficulty in achieving a rapid transference after methods which require prolonged action, probably accounts for the much higher mortality rate of specimens treated by standing in a small volume of sea-water, than for those treated by the injection of distilled water. Even in the latter cases, which were transferred to fresh sea-water within one minute of auto-

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