File:The American Museum journal (c1900-(1918)) (18160452605).jpg

Title: The American Museum journal
Identifier: americanmuseumjo18amer (find matches)
Year: c1900-(1918) (c190s)
Authors: American Museum of Natural History
Subjects: Natural history
Publisher: New York : American Museum of Natural History
Contributing Library: American Museum of Natural History Library
Digitizing Sponsor: Biodiversity Heritage Library

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46 THE AMERICAN MUSEUM JOURNAL fact due to a carmine pigment dissolved in the sap; it appears cliestnut because on an orange background. Knowing this, the problem was to get it on to another background, in order to bring out the wine-red color. We should have preferred white, but no white- rayed sunflowers are known. The near- est approximation is a very pale yellow, which we have found as a wild sport, but which has also been long in cultivation. In England it is called the primrose sun- flower, because the color is like that of an Eng- lish primrose. Crossing the full red sun- flower with the ))rimrose vari- ety, we got, as expected, off- spring like the red parent. These were raised in the greenhouse dur- ing the win- ter, to save a year, and were crossed with one another. Their offspring included chestnut-red, plain orange, primrose, and the expected wine-red, which is simply red on a primrose background. All this appeared, not only as expected, but nearly in the pro- portions which were deduced on theo- retical grounds. Thus we had the fol- lowino-:
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Species-)iybrid Heiianthug annuim (red) x petiolari-n. the latter being the seed parent. Grown in Boulder in 1917. The n. petiolaris parent was raised from seed collected in Oklahoma Chestnut-red Obtained ri Expected according to theor\- 69 ' AYine-red 25 23 Orange 19 23 Primrose 8 8 The wine-red, thus obtained according to definite rules of breeding, was an entirely new color variety, yet its quali- ties existed separately in its grandpar- ents. Just how it all works out, we will not attempt to explain in this arti- cle, but it is in accordance with the laws discovered by Gregor Mendel many years ago, and fully set forth in many recent works as "Mendelism."" It is often supposed that when a breeder desires to pro- duce new plants, he has only to cross different species ))ossessing do- sirable char- acters. Tlie chances of suc- cess in doing this vary very much according to the kinds of ))lants iTsed. Among the hot- liouse orchids, hybrids between different gen- era are common, and as they can be propagated by division, they are capa- ble of being increased without losing their char- acters. x\nnual sunflowers, which are propagated by seed, offer much greater difficulties. The annual species so far experimented with readily cross, and produce fertile seed. This seed gives rise to hybrid plants, which are themselves so nearly sterile that they cannot be offered horticulturally. On the other hand, all the varieties of the common sunflower, Helianthus annuus. seem to cross without any impairment of fertility. Even the great so-called Russian sunflower produces quite fer-

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