American naturalist, professor of anatomy and director of the Dept. of Biology at the Univ. of Pennsylvania, president of the Academy of Natural Sciences from 1882-91. These letters concern Leidy's scientific and professional interests, a few only treating of personal matters. Many deal with his active participation in the affairs of various local organizations, i.e. the Academy, the University of Pennsylvania, Swarthmore College, and the Wagner Free Institute of Science in Philadelphia. They reflect his wide interest in all phases of natural history, protozoology, embryology, parasitology, paleontology, anthropology, mineralogy and botany. Leidy wrote 229 of the letters, the remainder being signed by some 800 other scientists, as follows:

Signers:

Abbott, Chas. C. (2) 1859-64;

Addey, Harkinfield, 1870;

Agassiz, Alex (5) 1865-70;

Agassiz, Louis (10) 1851-58;

Agnew, D. Hayes (3) 1860-81;

Alexander, 0. 1868;

Allen, Harrison (4) 1884-88;

Allen, Wm. H. 1871;

Allman, John I. (4) 1875-80;

Amadeo y Antomarchi, Antorio Jose (2) 1885;

Ames, Alfred E. 1873;

Andrews, Garnett, 1858;

Andrews, F. 1862;

Apgar, A. C. 1878;

Atkinson, Mary N. (2) 1881-82;

Atkinson, Wm. B. (8) 1863-75;

Atlee, John F. (2) 1853-54;

Atlee, Walter F. 1868;

Austin, C. F. 1864;

Avery, John N. 1886;

Bailey, J. W. 1852;

Baird, Mary H. C. 1870;

Baird, S. F. (155) 1852-85;

Balfour, F. M. 1881;

Ballard, Harlan H. 1886;

Baltz, John D. 1891;

Baltzell, W. H. 1859;

Barber, Edwin A. (6) 1876-84;

Barcena, Mariano (7) 1875-81;

Barclay, R. D. 1872;

Barksdale, Randolph, 1879;

Barnard, W. S. 1874;

Barnum, N. T. 1882;

Barnwell, Jas. G. 1885;

Barr, Martin W. 1878;

Barrows, Sam. J. 1887;

Barton, Bolling W. (2) 1878;

Barton, J. M. 1884;

Bassett, Ebenezer D. 1858;

Bates, H. L. 1886;

Baur, G. 1888;

Beadle, E. R. (3) 1866-70;

Beates, Henry, Jr. 1878;

Becker, G. F. 1890;

Beebe, Edw. H. 1863;

Belfield, W. T. (2) 1886;

Bell, F. Jeffrey, 1890;

Bement, C. S. (16) 1869-84;

Bennett, Joseph M. 1884;

Bettany, G. T. (2) 1875-76;

Betten, Th. 1858;

Bickmore, Albert S. (2) 1874-76;

Biddle, Cadwalader (3) 1863-82;

Biddle, Caldwell K. (3) 1853-62;

Billings, John S. (7) 1871-86;

Binder, Jacob, 1884;

Binney, Amos (12) 1845-46;

Binney, W. G. (2) 1856-59;

Birkey, Wm. S. 1857;

Bishop, J. I. 1887;

Blackmore, Wm. 1875;

Blackwell, E. V. 1861;

Blake, Wm. P. (4) 1855-83;

Bland, T. 1857;

Blogg, James, 1875;

Bolles, Gertrude, 1887;

Bossange, Edw. 1854;

Bossange, Hector, 1854;

Bouve, Thomas T. ( 3 ) 1880-86;

Bowen, J. S. 1858;

Bowsfield, Edw. C. (2) 1885;

Boyer, Chas. S. (2) 1862-68;

Brady, Henry B. (2) 1879;

Braidwood, T. W. 1865;

Bringhurst, Robt. R. 1884;

Brinton, D. G. 1891;

Brinton, J. H. (5) 1862-63;

Brooke, Francis M. (2) 1887;

Brooks, W. K. (5) 1878-84;

Broome, G. W. 1881;

Brown, Arthur E. 1880;

Brown, W. Owen, 1859;

Buchanan, Florence, 1889;

Buck, Albert H. 1884;

Buckley, S. B. 1874;

Budd, Chas. H. (3) 1851-75;

Burgess, Edw. (3) 1880;

Burk, Jesse Y. (7) 1883-86;

Burmeister, H. 1884;

Burris, Cyrus, 1882;

Butler, John M. (3) 1855-56;

Butler, S. W. 1854;

Butler, Thomas, 1876;

The Leidy-F.V.Hayden correspondence was photocopied for use in 1986.