It's still not too late. For those who already have travel reservations or for those just contemplating the possibility of going to Europe this summer, there are numerous opportunities to study a wide variety of subjects in virtually any city or country of their choice.

Length of the courses varies from a week to a month. So if your plans are still not definite, one of the summer sessions listed below may be just the way to spend those few extra days. It's a thought, anyway.

Great Britain

England is the most popular choice of traveling students. Although the deadline has expired for this year's liberal arts courses at Edinburgh, Oxford, and London University, as well as for the Shakepeare seminars at Stratford-on-Avon, many opportunities remain for the summer study.

The National Student Association estimates that a student in England will spend about $150 per month for room, board, and tuition. Funds at the larger universities are available for needy American students. Applications at other institutions are not due until the session starts.

Literature courses are offered in late July by the University College in Leicester and in August by the University College of the Southwest in Exeter, Devonshire. The British Drama League holds two sessions, one at Chichester August 1 to 15, and the other at Alnwick, August 31 to September 9, on "Drama and the Theater." The University of Durham sponsors a training program for would-be archaeologists at Corbridge-on-Tyne in late July.

Dublin also opens its doors to visiting students over the summer. Trinity College gives a course on "The Arts in Ireland," University College will provide lectures on "Ireland and the Modern World" and instruction in Gaelic. Tuition for the two-to-three-week courses in only about $40.

France

All the French universities permit summer students to enroll for as little as two weeks of a session. The advantage is that the student does not have to spend the entire summer in one of the most expensive countries on the Continent. Monthly expenses, especially in Paris, may amount to $160 a month.

For those who want to stay on the French Riviera, the University of Aix Marseille offers courses in French language, literature and civilization at the coastal towns of Cannes and Nice. English and American literature will also be taught. The summer session begins in the middle of July and lasts till September.

The Fontainebleau Schools of Music and Fine Arts hold instruction in English on music, painting, sculpture, architecture, interior design, costumes, and scenery designs in the Chateau of Fontainebleau, July through September. Schools in Paris offer numerous language courses for Americans. Different level language schools include the Alliance Francaise, the Institut de Phonetique, specializing in pronunciation, and the Ecole Superieure for French teachers of other countries. Most of the sessions begin in July.

Social sciences are taught at the College European on the Left Bank's Boulevard St. Germain. Also in July, the Ecole du Louvre will hold month long courses on "The Archaeology of the Middle Ages" and "Modern Painting." An "American Summer Course" of liberal arts is available at the Sorbonne, starting July 1. A special course is even offered to those who are interested in "aerial photogrammetry" by the Ecole Nationale des Sciences Geographiques in the month of June. Tutition fees for most courses are as low as $10 to $20.

One of the few courses in Paris conducted in English will be the annual seminar on "Contemporary French Political and Economic Problems" at the Paris Institute of Political Studies in July.

Belgium and Holland

The Belgians offer one summer course on contemporary literature at the Free University of Brussels from July to August 18. A Brussels seminar on "17th Century Flemish Art" is limited to advanced art history students. Living expenses in Belgium are slightly less than in France.