The Department of Zoology, The IIS (Deemed to be) University, Jaipur, organized a guest lecture on “Philosophy and Physiology of pineal gland and melatonin” on 29th January 2019. The Guest speaker was Prof. Chandana Haldar, Professor and Former Director, Institute of Science and Head Department of Zoology, Banaras Hindu University, Varanasi. In her talk, she emphasized on Pineal gland physiology, Philosophy and importance of melatonin in human health. She also explained the relationship of melatonin with reproduction and immunity and also emphasized on photo-periodic transducer/Neuroendocrine Transducer/Hormone of darkness. Her lecture was very informative and it was a very good learning experience for students and faculty as well.