The appendix is not a lymph node, but it is packed with lymph tissues, as I
recall.

As for the bit about elephants, that may simply be of over-simplification.
Outside of the primates, I am trying to think of a big-brained herbivourous
animal.

 -p. 27 states that the appendix is a lymph node.  The=20
> > appendix is a little pouch; a lymph node is a complex filtering=20
> > structure of tissue filled with lymphocytes.
> >=20
>
>