He selects the subjects which he will study, and enters his name for these studies; but he can skip attendance.
The result of this system is, that lecture-courses upon specialties of an unusual nature are often delivered to very slim audiences, while those upon more practical and every-day matters of education are delivered to very large ones.

I heard of one case where, day after day, the lecturer's audience consisted of three students--and always the same three.

But one day two of them remained away.

The lecturer began as usual-- "Gentlemen," -- then, without a smile, he corrected himself, saying-- "Sir," -- and went on with his discourse.
It is said that the vast majority of the Heidelberg students are hard workers, and make the most of their opportunities; that they have no surplus means to spend in dissipation, and no time to spare for frolicking.

One lecture follows right on the heels of another, with very little time for the student to get out of one hall and into the next; but the industrious ones manage it by going on a trot.