Manuscript (79 p.) in the hand of J.P. Crozer Griffith, dated Upland, Delaware County, Pa., 28 May 1881, concerning the minute anatomy of the leaves of pines, or the genus Pinus, of the United States, with special reference to the determination of species. This item is evidently a manuscript version of the thesis that Griffith submitted for the degree of Doctor of Philosophy at the University of Pennsylvania. (The University's archival copy of the thesis is dated 1880, and has a slightly different title: The minute anatomy of the leaves of the genus Pinus.) Judging from Griffith's remarks in the present text, the thesis was probably written under the direction of Joseph Trimble Rothrock, professor of botany. Griffith examined authenticated specimens of the leaves of 31 different species, in transverse section. The manuscript consists of an introduction (p. 1-28); an analytical table (p. 30-32), which gives an overview of how he classified the specimens; and descriptions of the specimens (p. 33-79). The analytical table classifies the specimens according to the type of resin ducts (peripheral, fundamental, internal); the presence or absence of strengthening cells; and the shape of the section (circular, semicircular, broadly triangular, narrowly triangular). Included in the manuscript (tipped in, front flyleaf) is a letter from Griffith, addressed to Professor Rodney H. True, at the University of Pennsylvania, dated 5 May 1936, at the time that he made the gift of the manuscript to the Department of Botany . The manuscript is accompanied by a box of 36 slides, numbered 73 to 108 (see Box 2), representing the specimens referred to in the text. The slides, which were prepared by Griffith, are labeled with the species name as well as information about the source of each specimen, including the place and date where it was collected.
