This is what I found from the Benedictine Handbook:
"Cuculla is a formal choir robe, which may be worn over the habit or other clothes at liturgical solemnities. The Latin cuculus (hood) originally referred to a Roman hooded outer garment or cowl. Benedict mentions it in the Rule, Chapter 55, first paragraph. In recent tradition, it is black with 72 pleats (one for each chapter of the Rule). It is also the traditional death-shroud in many Benedictine communities."
Now we both know what a cuculla is and why it has 72 pleats.
On another note, I invite you to read an encyclical from Pope Pius XII from October 24, 1948.
"On Prayers for Peace in Palestine"
www.vatican.va/content/pius-xii/en/encyclicals/documents/hf_p-xii_enc_24101948_in-multiplicibus-curis.html