Plants of Iowa; a preliminary list of the native and introduced plants of the state, not under cultivation - Greene, Wesley. (Bishard brothers, printers, 1907)

Plants of Rhode Island : being an enumeration of plants growing without cultivation in the State of Rhode Island - Bennett, James Lawrence, 1832 -1904 (Providence Press, 1888)

Plants; a text-book of botany - Coulter, John Merle, 1851 -1928 (D. Appleton, 1907)

Plants : a text-book of botany - Coulter, John Merle, 1851 -1928 (D. Appleton and Company, 1907)

The Plasmodiophorales; including a complete host index, bibliography, and a description of diseases caused by species of this order - Karling, John S. (John Sidney), 1898 - (The author, 1942)

A pocket botanical dictionary; comprising the names, history, and culture of all plants known in Britain; with a full explanation of technical terms - Lindley, John, 1799 -1865 (J. Andrews, 1840)

Popular botany; the living plant from seed to fruit - Step, Edward, 1855 -1931 (H. Holt and company, 1913)

A popular history of British lichens - Lindsay, W. Lauder (William Lauder), 1829 -1880 (Lovell Reeve, 1856)

A popular history of British lichens, comprising an account of their structure, reproduction, uses, distribution, and classification - Lindsay, W. Lauder (William Lauder), 1829 -1880 (L. Reeve, 1856)

The Popular science monthly - Harry Houdini Collection (Library of Congress) (Popular Science Pub. Co., etc, 1889)

Pozsonyi Orvos-Termeszettudomanyi Egyesulet Kozlemenyei - Verein für natur- und heilkunde, Pressburg (1894)

Practical text-book of plant physiology - MacDougal, Daniel Trembly, 1865 -1958 (Longmans, 1908)

Prehistoric Europe, a geological sketch - Geikie, James, 1839 -1915 (E. Stanford, 1881)

Prehistoric Europe : a geological sketch - Darwin, Charles, 1809 -1882 (Edward Stanford, 1881)

A preliminary catalogue of the flora of New Jersey - Britton, Nathaniel Lord, 1859 -1934 (Office of the Survey, 1881)

... A preliminary catalogue of the flora of New Jersey - Britton, Nathaniel Lord, 1859 -1934 (Office of the survey, 1881)

A preliminary list of Maine fungi - Ricker, Percy Leroy, 1878 -1973 (1902)

The principles of botany, and of vegetable physiology / translated from the German of D.C. Willdenow - Willdenow, Karl Ludwig, 1765 -1812 (Blackwood, 1811)

Principles of scientific botany, or, Botany as an inductive science - Lankester, E. Ray Sir, (Edwin Ray), 1847 -1929 (Longman, Brown, Green, and Longmans, 1849)

Principles of scientific botany, or, Botany as an inductive science - Lankester, Edwin, 1814 -1874 (Printed for Longman, Brown, Green, and Longmans, 1849)

Proceedings - Nova Scotian Institute of Science. (1866)

Proceedings - Dorset Natural History; Archaeological Society.

Proceedings and transactions of the Natural History Society of Glasgow - Natural History Society of Glasgow. (The Society, 1883)

The Proceedings and transactions of the Nova Scotian Institute of Science - Nova Scotian Institute of Science. (Nova Scotian Institute of Science, 1906)

Proceedings - Cambridge Philosophical Society Mathematical and physical sciences - Cambridge Philosophical Society. (Cambridge Philosophical Society [etc.], 1892)

Proceedings - Dorset Natural History and Archaeological Society - Dorset Natural History; Archaeological Society. (1877)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1889)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1890)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1891)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1893)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1913)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1841)

Proceedings of the Bath Natural History and Antiquarian Field Club - Bath Natural History; Antiquarian Field Club. (1874)

Proceedings of the Bath Natural History and Antiquarian Field Club - Bath Natural History; Antiquarian Field Club. (1898)

Proceedings of the Biological Society of Washington - Smithsonian Institution (Biological Society of Washington, 1897)

Proceedings of the Biological Society of Washington - Smithsonian Institution (Biological Society of Washington, 1921)

Proceedings of the Biological Society of Washington - Smithsonian Institution (Biological Society of Washington, 2000)

Proceedings of the Boston Society of Natural History - Boston Society of Natural History. (Boston Society of Natural History, 1856)

Proceedings of the Bristol Naturalists' Society - Bristol Naturalists' Society (Bristol, England) (Bristol Naturalists' Society, 1879)

Proceedings of the Bristol Naturalists' Society - Bristol Naturalists' Society (Bristol, England) (Bristol Naturalists' Society, 1888)

Proceedings of the Bristol Naturalists' Society - Bristol Naturalists' Society (Bristol, England) (Bristol Naturalists' Society, 1910)

Proceedings of the Entomological Society of Washington - Entomological Society of Washington (Entomological Society of Washington, 1979)

Proceedings of the Entomological Society of Washington - Entomological Society of Washington (Entomological Society of Washington, 1984)

Proceedings of the Indiana Academy of Science - Indiana Academy of Science. ([s.n.], 1893)

Proceedings of the Indiana Academy of Science - Indiana Academy of Science. ([s.n.], 1901)

Proceedings of the Indiana Academy of Science - Indiana Academy of Science. ([s.n.], 1900)

Proceedings of the Indiana Academy of Science - Indiana Academy of Science. ([s.n.], 1911)

The Proceedings of the Iowa Academy of Science - Iowa Academy of Science (The Academy, 1895)

The Proceedings of the Iowa Academy of Science - Iowa Academy of Science (The Academy, 1897)

The Proceedings of the Iowa Academy of Science - Iowa Academy of Science (The Academy, 1905)

Proceedings of the Linnean Society of London - Linnean Society of London. (Published for the Linnean Society of London by Academic Press [etc.], 1848)

Proceedings of the Linnean Society of London - Linnean Society of London. (Published for the Linnean Society of London by Academic Press [etc.], 1855)

Proceedings of the Linnean Society of New South Wales - Linnean Society of New South Wales. (Linnean Society of New South Wales, 1933)

Proceedings of the Malacological Society of London - Malacological Society of London (Dulau, 1898)

Proceedings of the Malacological Society of London - Malacological Society of London (Dulau, 1912)

Proceedings of the Malacological Society of London - Malacological Society of London (Dulau, 1919)

Proceedings of the Malacological Society of London - Malacological Society of London (Dulau, 1918)

Proceedings of the Malacological Society of London - Malacological Society of London (Dulau, 1921)

Proceedings of the Natural history society of Dublin for the session ... - Natural History Society of Dublin. (Printed for the Society, 1878)

Proceedings of the Rochester Academy of Science - Rochester Academy of Science. (The Academy, 1889)

Proceedings of the Rochester Academy of Science - Rochester Academy of Science. (The Academy, 1894)

Proceedings of the Royal Irish Academy - Royal Irish Academy. (Royal Irish Academy, 1909)

Proceedings of the Royal Society of London Series B Containing papers of a Biological character - Royal Society (Great Britain) (Printed for the Royal Society and sold by Harrison & Sons, 1914)

Proceedings of the Royal Society of London - Royal Society (Great Britain) (The Society, 1875)

Proceedings of the United States National Museum - Smithsonian Institution (Smithsonian Institution Press, [etc.], 1886)

Prodrome de la flore Belge - De Wildeman, Emile 1866 -1947 (Alfred Castaigne, 1898)

Prodrome de la flore Belge - De Wildeman, Emile 1866 -1947 (Alfred Castaigne, 1899)

Prodrome de la flore belge - Wildeman, E. de (Emile), 1866 -1947 (A. Castaigne, 1898)

Prodromo della storia naturale generale e comparata d'Italia ... - Marmocchi, Francesco Constantino, 1805 -1858 (Società editrice fiorentina, 1844)

Prodromus florae Batavae - Dozy, F. (Frans), 1807 -1856 (Sumptibus Societatis, apud J. Hazenberg, 1850)

Prodromus florae stargardiensis : continens plantas in Ducatu Megapolitano-Stargardiensi S. Strelitzensi sponte provenientes - Schultz, Karl Friedrich, 1765 -1837 (sumtibus C. F. E. Spaethen, 1806)

Prodromus systematis naturalis regni vegetabilis, sive, Enumeratio contracta ordinum generum specierumque plantarum huc usque cognitarium, juxta methodi naturalis, normas digesta - Candolle, Augustin Pyramus de, 1778 -1841 (Sumptibus Sociorum Treuttel et Würtz, 1838)

Prof. dr. Thomé's Flora von Deutschland, Österreich und der Schweiz, in wort und bild, für schule und haus ... mit ... - Migula, W. (Walter), 1863 -1938 (1910)

Protists and disease : vegetable protists: algae and fungi, including Chytridiineae, various Plassomyxinae, the causes of molluscum contagiosum, smallpox, syphilis, cancer, and hydrophobia - Clarke, J. Jackson (James Jackson), 1860 -1940 (Bailliere, Tindall & Cox, 1922)

Protists and disease. Vegetable protists; Algae and Fungi, including Chytridiineae; various Plassomyxinae, the causes of molluscum contagiosum, smallpox, syphilis, cancer, and hydrophobia; together with the Mycetozoa and allied groups - Clarke, J. Jackson (James Jackson), 1860 -1940 (Baillière, Tindall & Cox, 1922)

Protozoology - Hall, Richard P. (Richard Pinkham), 1900 -1969 (Prentice-Hall, 1953)

Protozoology - Kudo, Richard R. (Richard Roksabro), 1886 -1967 (C. C. Thomas, 1954)

Protozoology - Kudo, Richard R. (Richard Roksabro), 1886 -1967 (C.C. Thomas, 1946)

Protozoology - Kudo, Richard R. (Richard Roksabro), 1886 -1967 (Thomas, 1939)

A provisional host-index of the fungi of the United States - Farlow, W. G. (William Gilson), 1844 -1919 (1888)

Psyche - Cambridge Entomological Club. (Cambridge Entomological Club, 1877)

Psyche - Cambridge Entomological Club. (Cambridge Entomological Club, 1924)

Publication. Field Columbian Museum Botanical series - Field Columbian Museum. (Field Columbian Museum, 1896)

Publication. Field Museum of Natural History Botanical series - Field Museum of Natural History. (Field Museum of Natural History, 1923)

Quarterly journal of microscopical science (J. and A. Churchill [etc.], 1854)

Quarterly journal of microscopical science (J. and A. Churchill [etc.], 1855)

Quarterly journal of microscopical science (J. and A. Churchill [etc.], 1857)

Quarterly journal of microscopical science (J. and A. Churchill [etc.], 1860)

Quarterly journal of microscopical science (J. and A. Churchill [etc.], 1864)

Quarterly journal of microscopical science (J. and A. Churchill [etc.], 1880)

Quarterly journal of microscopical science (J. and A. Churchill [etc.], 1898)

Quarterly journal of microscopical science (J. and A. Churchill [etc.], 1853)

Rambles in search of flowerless plants - Plues, Margaret (Journal of horticulture & cottage gardener office; [etc., etc.], 1864)

Recente und im Löss gefundene Landschnecken aus China - Kaiserl. Akademie der Wissenschaften in Wien. Mathematisch-Naturwissenschaftliche Klasse. (Kaiserl. Akademie der Wissenschaften, 1883)