Lobes contain smaller lobules, which contain adenomeres, the secretory units of the gland. The lobes are further divided into bronchopulmonary segments and pulmonary lobules. The fibrous tissue separates the gland into lobules. These cells are grouped together in lobules separated by connective tissue. These alveoli join to form groups known as "lobules". The intralobular ducts of the lobules drain into the interlobular ducts between lobules. The glandular structure of the testis consists of numerous "lobules". Both the vermis and the hemispheres are composed of lobules formed by groups of folia. It is composed of adipocytes, which are grouped together in lobules separated by connective tissue. The gland is internally divided into lobules. Most breast cancers start in the ducts or lobules, and are adenocarcinomas. On the maternal side, these villous tree structures are grouped into lobules called cotyledons. The epithelium forms fine lobules, and develops into a sponge-like structure. Microscopically, each liver lobe is seen to be made up of hepatic lobules. These trabecules divide the tonsil into lobules.