自残是某些动物在生死存亡的紧急关头,自动弃尾、断腿、和抛肠丢肚的一种自卫现象。而再生是动物在自断或损伤的部位重新生成的过程。自残与再生是对立的统一,是“物竞天择”的必然结果。环节动物的蚯蚓,靠近头部前端的前8节细胞分裂快,再生功能也就特别强;从第9节到第14节虽有再生功能,但细胞分裂速度已趋缓慢,而且某些器官就不可能重新修复;第十五节以后切断虽仍有再生功能,但将变成一条没有头部而有二条尾巴的“怪蚓”了。两栖动物的蝾螈,爬行动物的蜥蜴,哺乳动物的山鼠,当你抓住尾部时,尾巴就自动断裂脱落。过了一段时期一条尾巴在断裂处 Self-mutilation is a kind of self-defense phenomenon in which some animals are killed at the critical moment of their life and death. Regeneration, on the other hand, is the process by which an animal regenerates at a site that has been severed or damaged. Self-mutilation and regeneration are the opposite of unity and are the inevitable result of “natural selection.” Earthworms of annelids, near the front of the head of the first 8 cell division fast, regenerative function is particularly strong; from section 9 to section 14 although the regenerative function, but the cell division speed has been slow, and some organs on It is impossible to re-repair; after the fifteenth section cut off although there is still a regenerative function, but will become a no head and two tails of the “strange earthworm.” Amphibian salamander, reptile lizard, mammalian mountain rat, when you catch the tail, the tail will automatically break off. After a period of time a tail was broken