Known as the Early Journal Content, this set of works include research articles, news, letters, and other writings published in more than 200 of the oldest leading academic journals. The works date from the mid--seventeenth to the early twentieth centuries. We encourage people to read and share the Early Journal Content openly and to tell others that this resource exists. People may post this content online or redistribute in any way for non--commercial purposes. Read more about Early Journal

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... ntent at http://about.jstor.org/participate--jstor/individuals/early-journal--content. JSTOR is a digital library of academic journals, books, and primary source objects. JSTOR helps people discover, use, and build upon a wide range of content through a powerful research and teaching platform, and preserves this content for future generations. JSTOR is part of ITHAKA, a not--for--profit organization that also includes Ithaka S+R and Portico. For more information about JSTOR, please contact support@jstor.org. I9II] CURRENT LITERATURE I47 NOTES FOR STUDENTS Graft hybrids and chimeras.-The large amount of recent work on graft hybrids, which has resulted in such astonishing discoveries as to their exact nature, seems to call for a collective review. In i825 M. ADAM, a French horticulturist, by grafting Cytisus purpureus (a small tufted species) on Laburnum vulgare (an arborescent species) was much surprised to find that there resulted a shoot with somewhat intermediate characters. While the original individual has long been dead, the new form has been propagated by grafting and is somewhat common in cultivation; to it there has been given the name Laburnum Adami, and generally it has been regarded as a graft hybrid. Scarcely second in reputation to this, the most famous of the "graft hybrids," is Craiaegomespilus, which is supposed to be a graft hybrid between Crataegus monogyna and Aliespilus germanica; in this case the original tree is said still to exist in Lorraine. A third supposed case of a graft hybrid is the Bizzaria orange, which is thought to have arisen through the intergrafting of Citrus Aurantium and C. medica. While much study has been made of these peculiar plant forms, it is only very recently that their nature has been understood. The present phase of graft hybrid investigation dates from a paper by HANS WINKLER, published in I907 .3 Although the results of this first paper were somewhat disappointing, they deserve mention, because they opened up a new method of investigation. A scion of Solanum nigrum was grafted on S. Lycopersicum, and after growth had been resumed, a transverse cut was made in such a way as to sever both stock and scion, it being hoped that adventive shoots would grow from the cut surface along the line of contact of stock and scion. Such adventive shoots actually appeared, and in one case the new shoot involved tissues of both stock and scion. However, the new form was not a graft hybrid, for clearly one side of the shoot was Solanum nigrum and the other S. Lycopersicum; to this peculiar structure WINKLER gave the suggestive name chimera. So sharply marked was the line between the tomato and the nightshade that some leaves were partly of one species and partly of the other. WINKLER'S method soon yielded the results he had been seeking, for in i908 he announced the production of a true graft hybrid,4 a notable result, since never before had this been done under exact experimental control. To the new form there was given the name Solanum thbingense, in honor of the university town where the plant was produced. Out of 268 grafts between the tomato and the nightshade, there arose over 3000 adventitious shoots, among which there were five chimeras and the supposed graft hybrid Solanurn tubingense; the latter, while intermediate in character, is somewhat closer to the nightshade than to the tomato. Early in I909 WINKLER reported 3 WINKLER, HANS, Ueber Propfbastarde und pflanzliche Chimdren. Ber. Deutsch. Bot. Gesell. 25:568-576. figs. 3. I907; see BOT. GAZETTE 47:84. I909. 4 ---, Solanum tubingense, ein echter Propfbastard zwischen Tomate und Nachtschatten. Ber. Deutsch. Bot. Gesell. 26a:595-608. figs. 2. i908; see BOT. GAZETTE 47:250. I909.