This 55th annual report on collegiate enrollments examinies the statistics, and presents interpretations and trends in four-year and related institutions of higher education. Of 1,457 responding institutions in the U.S., Puerto Rico, and related territories, there were 4,731,376 full-time and 1,922,975 part-time students, a 6,654,351 grand total of students. General observations indicated (1) grand total enrollments represented a rise of 3.7 percent as compared to 1.8 percent in 1973-74; (2) about 70 percent of all students attending institutions in this study are full-time attendees, indicating a rise of 2 percent, which is up from the 0.4 percent reported for 1973-74 and the 0.4 percent decrease of 1972-73; (3) in the 17 unitary state systems reporting for 1974-75, there were 1,089,781 full-time students, who accounted for an increase of 4.3 percent; (4) the 75 public-complex universities reporting for 1974-75 counted 1,335,369 full-time students, for a modest gain of 1.8 percent; (5) private complex universities show full-time enrollment recovery, with a gain of 2.2 percent; (6) as recently as 1969-70, 148 reporting institutions were classfied as teacher colleges, while for 1974-75, only 32 schools remained in the independent teachers and universities category; because some of them were dissatisfied with this category for 1974-75, it was deleted and the schools were reclassified. (MJM)