Answer: The hilum is the point at which arteries carrying nutrients and lymphocytes enter the lymph node and veins leave it. Afferent lymphatic vessels enter the lymph node through the capsule peripherally and efferent lymphatic vessels leave the node via the hilum.
The plants provide food and accommodation in the form of food bodies and nectar as well as hollow thorns which can be used as nests. The ants return this favor by protecting the plants against herbivores
