Table 1. Hourly Means and Standard Errors in the Group A of Cats of the Duration (in minutes) and Number of Slow Wave Sleep (SWS) and Paradoxical Sleep (PS) Episodes in Baseline Experiments and after Microinjections of Saline (50 nl) and Morphine (2.4 X 10 sup -9 M in 50 nl of Saline in the NST