The Collaborative International Dictionary of English v.0.48:

Peyer's glands \Pey"er's glands`\ [So called from J. K. Peyer,
   who described them in 1677.] (Anat.)
   Patches of lymphoid nodules, in the walls of the small
   intestiness; agminated glands; -- called also Peyer's
   patches. In typhoid fever they become the seat of ulcers
   which are regarded as the characteristic organic lesion of
   that disease.
   [1913 Webster]