Our journey in the company of blood and lymphatic vessel ends here. We encountered history, evolution, comparative biology, and the most advanced and current research in the field. We also discussed the philosophical aspects and the changes and evolution of concepts and paradigms. The specialist reader will hopefully forgive me for some shortcuts that cannot be avoided because this book is also written for a wider public. Nevertheless, I think I have covered the essential aspects concerning this subject. I have tried to use accessible language for a wider audience. Although sometimes a more technical language has been used, this has only been done to bring more precision to certain aspects of the ongoing research on vascular development.

I leave the last word to William Harvey, who contributed to the scientific revolution in the vascular biology field on which we are all dependent today. He wrote in the introduction to his famous book, Exercitatio De Motus Cordis et Sanguinis in Animalibus, the following:

My dear colleagues, I had no reason to inflate this treatise in a large volume by quoting the names and writings of the anatomists, or to demonstrate the extent of my memory, my knowledge, and my efforts; because I profess both to learn and to teach anatomy, not from books, but from dissections; not from philosophical theories, but from nature; and then because I do not think it is right or good to strive to take from the elders all due honor, nor to argue with the moderns, and to enter into a controversy with those who have excelled in anatomy and were my teachers. I would not like to accuse anyone who was sincerely concerned about the truth, or to accuse anyone who has fallen into error, of knowingly lying. I am a believer in the truth alone, and I can say that I have used all my efforts to try to produce something that should serve the good, be profitable to scientists and useful to the letters.

Farewell, highly esteemed doctors, and kindly think of your anatomist,

William Harvey