Hi Pilou,
The link works for me, but I find you can also just enter http://www.illustratedgarden.org to get to the site and browse titles from there.
Yes, I could never forget Haekel and his amazing (other worldly) illustrations. Thanks again for pointing us to his work on line!
Hi Nuts,
At the time I worked there, the rare-book library had a horribly limited budget to finance one of the better private botanical book collections in the US AND at the same time attempt to preserve their collection of rare volumes kept in a non-airconditioned caged area with no humidity control. Back then it was a losing battle against the harsh St. Louis summers.
The head librarian was a self-taught botanist and librarian and binder of books (I often wondered if he did more harm than good in his attempts at restoration). I was first hired to help maintain the general collection of journals and periodicals and repair damaged books from the open stacks. Gradually he trusted me enough to start working on restoration of some of the less valuable but rare volumes. The work consisted mostly of reconstructing signatures, stripping and restitching bindings and in some cases, replacing entire covers. Sometimes one book would take two or three weeks. On-the-job training kept it interesting for the time I was there but I wasn’t tempted into any kind of a career. 
Looking back I mostly remember these amazing illustrations.
Sven