10 Collection between 1892 and 1941, when the Society relinquished care of it. The Bailey Collection: 1941-present The use of the Bailey Collection since its receipt by the Farlow Herbarium in 1941 has been apparently meagre. I have found only that the Academy of Natural Sciences of Philadelphia had borrowed a small portion of it, that N. Ingrahm Hendey had used it in 1953 and designated several types of Bailey's species' names of diatoms, and that Robert Ross had perused it in 1962 and left notes concerning its reorganization. The present Bailey Collection primarily with respect to its diatom materials is composed of three major parts, each deriving its organization from the 1857 bequest: A) A MICROSCOPIC SLIDE COLLECTION including related paleographs and a catalogue of the slides and their contents. The 1,216 slides contained in this collection are the remnants of the "Microscopical Collection" described in the 1857 bequest. With a few exceptions, each slide bears a number between 567 and 2,185 scratched into the glass. This collection currently includes slides that I found in 1976 in 1) 24 octavo cardboard slide boxes, each possessing a label on its inside cover indicating "Boston Society of Natural History/Bequest of/Prof. J.W. Bailey/April, 1857" (Table 1), 2) two century wooden slide boxes each containing c. 100 slides, 3) two wooden folders bearing 30 large and odd-sized glass slides, 4) an unnumbered small green box with J.W. Bailey's name on it found at the Academy of Natural Sciences of Philadelphia and containing slides numbered from 1527 to 1537, and 5) an octavo slide box from the Boston Society of Natural History general slide (non-Bailey) collection containing slides numbered from 1538 to 1542 and from 1752 to 1796. All these materials were found in