is roughly unchanged over twenty-eight years for the Ivy League. But the 6 other private universities have experienced a substantial fall in the proportion of full professors. This may be explained in part by the growth of research programs. It is also explained by a rise in the percentage of associate professors. The proportion for women's colleges has not changed considerably, but there has been a substantial decline of full professors in the 20 liberal arts colleges, which is only partly made up by a rise in the percentage of associate professors. The decline of full professors is especially marked in large urban and large Catholic institutions. Here, where enrollment has been rising greatly and costs increasing, the response has been to depend upon a younger faculty. It should be pointed out, however, that a rise in the rate of growth of enrollment would lead us to expect some tendency in this direction.