UNIVERSITY PARK, Pa. -- It's the end of the semester at Penn State, and seniors are checking off the boxes. Last class -- check. Last exam -- check. Last lab, last paper, last grade -- check. Cap-and-gown selfie at the Nittany Lion shrine and an ice cream cone at the Berkey Creamery -- check.

This weekend, more than 13,000 students will join the growing family of Penn State alumni as the University holds spring commencement ceremonies at all of its campuses across the Commonwealth. At University Park, 13 ceremonies will take place over the weekend of Friday, May 9, through Sunday, May 11. Every college will hold its own event, from the Colleges of Engineering and Earth and Mineral Sciences at 8 p.m. on Friday, to the College of Agricultural Sciences at 3:30 p.m. on Sunday, followed by the last ceremony of the weekend, the Graduate School, at 6:30 p.m.

This weekend's commencement exercises are the 376th of their kind since the University's founding in 1855. While many things have changed since then -- most notably the number of graduates (13 in the first class of 1861) and the locations of the ceremonies (from the original Old Main lawn amphitheater to today's Bryce Jordan Center and Eisenhower Auditorium) -- the overall exercises still uphold traditions that are as old or older than the University itself.

If you’ve ever been to a commencement ceremony, or an academic convocation, you might have wondered about some of the traditions of the ceremony.

At Penn State, every college and campus has a slightly different way of doing things, said Barbara Ettaro, director of campus and community affairs. But commencement as a ceremony worldwide is patterned after a ritual that has its origins in the history of higher education and the formation of early universities in Europe during the Middle Ages.

The Academic Regalia

Caps and gowns make an event recognizably a commencement ceremony -- from the mortarboard and black gown of the undergraduate, to the slightly more formal robes of the graduate student, to the often elaborate and colorful hoods and robes worn by faculty, who have earned degrees from institutions around the world.

The academic regalia worn by participants also has its origins in the Middle Ages. In the 12th and 13th centuries, the majority of scholars were also clerics in the church and wore robes similar to those of their monastic orders. Caps and hoods were a necessity in the drafty buildings of the era. These early scholars decided that the hood would be made distinctive by differences in color, trim and binding, to distinguish different academic disciplines. The U.S. established a standard of dress in 1895, often referred to as the Intercollegiate Code.

Gowns worn by faculty vary according to the academic degree held by the wearer. Undergraduate gowns are plain with normal sleeves. Master’s sleeves are pointed. Trimming is reserved for doctoral gowns, which are faced in front with long panels of velvet and have three bars of matching material on the rounded sleeves.

Hoods, usually worn only by those who hold master's and doctoral degrees, are the most distinctive feature and vary in length according to the type of degree held, with the lining showing the official colors of the institution that conferred the degree. Doctoral candidates are traditionally given their hoods by their faculty advisors at the Graduate School ceremony.The velvet edging of the hood indicates the character of the degree it represents: blue for philosophy; light blue for education; brown for fine arts; blue violet for architecture; copper for economics; drab for business administration; golden yellow for science; green for medicine; sage green for physical education; orange for engineering; pink for music; russet for forestry; and white for arts, letters and the humanities.

The cap, or mortarboard, is square and usually is the same color and style for all degrees, although you might see a style of soft cap called a tam worn by doctorates. The standard tassel for undergraduates is white, while the doctoral cap might have a tassel of gold. Undergraduates wear the tassel on the right side of the cap until the moment the degree is conferred at the ceremony.

The University Mace

The University Mace, another tradition passed down from medieval times, is a baton made of wood and brass, carried by a faculty representative at the head of the academic procession and recession during commencement ceremonies. According to University Marshal Bob Melton, professor of aerospace engineering and director of undergraduate studies, the mace symbolizes the academic authority of the University and is a common symbol among academic institutions.

The large mace used in the Bryce Jordan Center was carved in 1957 from a newel post -- an upright post that supports the rail of a staircase-- saved from the original Old Main building when it was rebuilt in 1929. Smaller replicas were made from balusters of the roof of University House, the former President’s residence on campus, and are used at Eisenhower Auditorium.

The University Chain of Office and Medal

The University Chain of Office and Medal, worn by the president of the University at commencement and other times when academic regalia is appropriate, was introduced in the fall of 2002 as a symbol of the responsibilities of the Office of the President and the continuity of that position, as one president passes the chain and medal on to the next.

The links of the chain are engraved with the names of all of the presidents of Penn State, with the current president's name on the link directly above the medal. On the medal itself is a likeness of the official University seal, the centerpiece of which is the office seal of the Commonwealth of Pennsylvania, symbolic of Penn State's three-fold mission of teaching, research and public service. This weekend will mark the last ceremonies that President Rodney A. Erickson will preside over before his retirement.

The Invocation

The words spoken at the beginning of the ceremony are an essential part of the ritual and are virtually the same for every college. Acting as master of ceremonies, a University Marshal -- part of Penn State’s dedicated group of faculty who volunteer their time and attention to ensuring that academic events such as commencement run smoothly – will set the tone during the invocation:

“Good afternoon. For the 376th time, The Pennsylvania State University conducts commencement exercises. All are in their places. While the day is one of joy and celebration, the commencement ceremony itself calls for dignity and decorum. This is one of the great days of a lifetime for our graduates, their families and friends. Therefore, we request everyone's cooperation in according this ceremony the quiet respect it deserves. These exercises for the 2014 Spring Semester are hereby called to order.”

Although most of Penn State’s colleges now recite the invocation in English, the College of the Liberal Arts' marshal lends further gravitas to the ceremony by reciting the invocation in Latin, then repeating it in English: “Omnes rite ac recte consederunt." ("All are in their places.")

The Alma Mater

Music also is an integral part of the commencement experience. At the beginning of the exercises, Centre Brass Quintet plays as faculty and student marshals of high distinction representing their various disciplines process into their places. The quintet also accompanies the songleader -- a graduating School of Music student -- as he or she leads the audience in singing first the National Anthem at the top of the ceremony, and then Penn State's Alma Mater at its close.

The Alma Mater was written in 1901 by Fred Lewis Pattee, longtime professor of American literature, who in his time bemoaned the fact that Penn State had no college song which would nourish college spirit and loyalty as other schools had.

The song was first sung at the Alumni Dinner during commencement week that June. Pennsylvania Gov. James A. Beaver, president of the Board of Trustees, immediately proclaimed it "the official song of Penn State," with President George Atherton's agreement. A copy of the Alma Mater in Pattee's original handwriting is on display in the Penn State University Archives.

"May no act of ours bring shameTo one heart that loves thy name,May our lives but swell thy fame,Dear old State, dear old State."

A threshold between the past and the future, commencement is a celebration of accomplishments and a promise of great things to come. As the newly graduated alumni are sent out into the world, hopefully they take with them memories of Penn State they will cherish for the rest of their lives as they embrace the future that awaits them.