File:Contributions from the Botanical Laboratory, vol. 9 (1892) (20500120238).jpg

Title: Contributions from the Botanical Laboratory, vol. 9
Identifier: contributionsfro09univ (find matches)
Year: 1892 (1890s)
Authors: University of Pennsylvania. Botanical Laboratory
Subjects: Botany; Botany
Publisher: Philadelphia : University of Pennsylvania Press
Contributing Library: Penn State University
Digitizing Sponsor: Lyrasis Members and Sloan Foundation

View Book Page: Book Viewer
About This Book: Catalog Entry
View All Images: All Images From Book
Click here to view book online to see this illustration in context in a browseable online version of this book.

Text Appearing Before Image:
II
Text Appearing After Image:
FIRST OBSERVED HYBRIDIZATION IN PLANTS His Witch-hunting activities have led posterity to ^-^^;^^> ^^%^,"^^^^^^ Mather "contributed my two mites to the way wherem vegetation is earn i o"' ^" contributio^i is the earliest recorded observation of natural hybridization in plants. SOME FORGOTTEN RECORDS OF HYBRIDIZATION AND SEX IN PLANTS 1716-1739 Conway Zirkle Department of Botany, University of Pennsylvania THE first half of the eighteenth century was a time of exceptional botanical activity in the English colonies along the Atlantic Coast of North America. A new country filled with strange and interesting plants had just been opened for exploration and European botanists were anxious for specimens. Medicinal plants were in great demand and any educated colon- ists who sent seed or herbaria sheets to England or the Continent could be as- sured of an interesting and profitable correspondence with the plant im- porters. The colonists who collected, systema- tized and recorded the distribution of the new plants seem to have been ex- ceptionally able. They kept in close touch with the development of botany in Europe, visited and wrote letters to each other and exchanged ideas and specimens. They imported microscopes, investigated plant anatomy, especially the anatomy of the flower, and devised a number of physiological experiments. The most prominent men in the colon- ies were keenly interested in this local scientific development and some even joined in the experimentation. The European botanists were cer- tainly informed of the work of the Americans, although the very real con- tributions made by the latter, in fields other than taxonomy, have been, with a single exception, completely forgotten. Most biologists have been so im- pressed by the overwhelming adequacy of Sachs' History of Botany (1530- 1860) that any important botanical con- tribution which he failed to record is apt to remain unknown. Moreover, so greatly is Sachs' judgment admired and his fairness recognized (except perhaps in his treatment of Linnaeus), that he has become the principal arbiter of priority claims even in such a con- fused subject as that of the discovery of sex in plants. Sachs' evaluation of the contributions of the different work- ers in this field is still generally ac- cepted. In order to prove that plants repro- duce sexually it is necessary to show, first, that viable seeds can not be pro- duced without the cooperation of some element (pollen) which might be inter- preted as male, and, second, that both this hypothetical male element and the egg bear factors which influence the progeny. Camerarius (1694) is cited by Sachs as the first investigator to prove experimentally that pollen is nec- essary for seed development, while Koelreuter (1761) is credited with hav- ing made the first systematic study of plant hybridization, proving incidentally that both parents contribute to the off- spring. Sachs rightly emphasized the importance of Koelreuter's work for, as far as he knew, there were no reliable records of plant hybrids before 1761. In fact he mentions only two instances of species crossing before Koelreuter's experiments and both were considered somewhat dubious. He said of the first, "Bradley is our authority for the statement that a gardener in London had obtained a hybrid between Dianthus caryophylhis and Dianthus harhatns by artificial means as early as 1719" (Sachs, p. 406). The second instance is re- corded just as briefly, "Soon after allu- sion is made (by Linnaeus, 1735) to the artifices used by gardeners to obtam hybrid tulips and cabbages, but the mat- ter is treated rather as agreeable tri- fling" (Sachs, p. 400). Haartman on 433

Note About Images