How do I retrieve all elements in a list that are between two elements or two groups of elements in Python?

consider a list a = ['Anatomy', 'of', 'the', 'Human', 'Body', 'Henry', 'Gray', 'CONTENTS', 'I.', 'Embryology', '1.', 'The', 'Animal', 'Cell', '2.', 'The', 'Ovum', '3.', 'The', 'Spermatozoön', '4.', 'Fertilization', 'of', 'the', 'Ovum', '5.', 'Segmentation', 'of', 'the', 'Fertilized', 'Ovum', '6.', 'The', 'Neural', 'Groove', 'and', 'Tube'] How would you create a program that picked out elements based on other elements easily? Say I want the elements between 'The' and int + '.' to be stored in a list. Or store 'Ovum' in a list named 'Fertilization' because 'Ovum' is between 'The' and int + '.' and 'Fertilization' is before 'of' and after int + '.'