The study presented herein was performed in partial fulfillment of the requirement for the degree of Master of Science (Anatomy)of the All India Institute of Medical Sciences, New Delhi, in 1985. I wish to express my gratitude to my teacher, Dr. (Mrs) Kiran Kucheria, for her guidance and encouragement. This work is dedicated to the patients suffering with the dreadful disease of cancer, who have willingly given their blood, without whose cooperation this work would not have been possible.