This section is through the dermis of the skin over the nipple of the breast.   There are bundles of smooth muscle (lighter staining) running in the dense pink stained connective tissue. Be able to find these on your slide 79.

Large lactiferous sinuses can be found in the slide with the section of the nipple.  These are lined with stratified cuboidal epithelium and are the culmination of lactiferous ducts that originate from mammary gland ducts.