Plz tell me concise description of stages of anesthesia!

Out of date concept: The guidel signs of anesthesia relate to an ether induction and maintenance. The last ether anesthetic was done in '55. There were 4 stages. Stage 1 was the initial introduction of the ether, breath holding, altered consciousness but still respond to stimulus. Stage 2 is agitation, irregular breathing, random movements, stage 3 surgical plane, regular shallow breathing, stage 4 stops breathing.

1,2,3,4: Stage 1-The period between awake and unconsciousness. Patient can talk to you. Stage 2-"excitement" stage-delerium, breath holding, irregular breathing can occur. With modern drugs, this stage is passed quickly through to Stage 3-Surgical anesthesia, muscles relax, breathing becomes shallow, patient ready for surgery. Stage 4- Overdose, this stage is avoided.