Antoine Louveau and colleagues describe lymphatic vessels in the central nervous system (Nature 523, 337–341; 2015), suggesting that “the unique location of these vessels may have impeded their discovery to date”. However, these findings are not without precedent.

The first description of a lymphatic circulation in the head was soon forgotten (G. Schwalbe Z. Med. Wiss. 7, 465–467; 1869), as were other early landmark experiments (J. B. Brierley and E. J. Field J. Anat. 82, 153–166; 1948). These included half a dozen seminal contributions in the 1960s from a Hungarian group led by the late neurologist Endre Csanda and lymphologist Mihaly Földi.

This group of researchers described the existence and significance of a lymphatic system in the central nervous system, stating that “in striking contrast to the textbook opinion, lymph drainage plays an important part in fluid circulation of the brain”. They identified “well-defined connections between the subarachnoid space and the cervical lymph system in the nasal cavity, in the orbita and in the region of the jugular foramen” (M. Földi et al. Angiologica 5, 250–262; 1968).

Perhaps old papers that are not available as online PDFs are easily overlooked in today's literature searches, depriving many of our scientific predecessors of the recognition they deserve.