HYBRIDISATION AND WHEAT HYBRIDS 361 



that the greater vigour and yield of some wheats may be due to the fact 

 that they cross more frequently than the less prolific types. 



The production of artificial hybrids of wheats appears to have been 

 first attempted in this country by Thomas Andrew Knight about the end 

 of the eighteenth century. After successfully crossing peas he tried the 

 hybridisation of wheat, but states in his Essay on the Fecundation of 

 Vegetables (1804) that it " did not succeed to my expectations," and goes 

 on to say : " I readily obtained as many varieties as I wished by merely 

 sowing the different kinds together : for the structure of the blossom of 

 this plant (unlike that of the pea) freely admits the ingress of adventitious 

 farina, and is thence very liable to sport in varieties." 



In 1846 Mr. Maund of Bromsgrove exhibited hybrid wheats at a 

 meeting of the English Agricultural Society (Gardener's Chronicle, 1846, 

 p. 601), and in the same year Hugh Raynbird produced the hybrid Piper's 

 Thickset $ x Hopetoun <$ , the female parent a red-chaffed wheat with 

 short dense ears, the pollen parent a lax-eared form with white chaff. 

 The few hybrid grains obtained were sown in September and the " roots " 

 divided in January. ' The produce," he states, " was many kinds both 

 of red and white wheat ; some of the ears bore a perfect resemblance to 

 the Piper's Thickset, others partook of the character of the Hopetoun in 

 everything except in the colour of the chaff, others had half the ear thin 

 and open, and the rest close set, thus in the same ear showing the char- 

 acteristics of each kind." 



One of Raynbird's hybrids was awarded a gold medal in 1848 by the 

 Highland and Agricultural Society of Scotland, and several produced by 

 Maund and Raynbird were exhibited at the Great Exhibition of London 

 in 1851. 



These were the first hybrid wheats grown on a large scale. 



From about 1850 to 1870, Patrick Shirreff of Haddington in Scotland 

 paid especial attention to the improvement of cereals and produced 

 several hybrid wheats. 



In the early 'seventies of the nineteenth century Pringle and Blount 

 in the United States, Vilmorin in France, and Rimpau and Heine in 

 Germany were all actively engaged in hybridising wheats. Since that 

 date the crossing of this cereal has been extensively practised in a great 

 many countries. 



Little is known of the conditions upon which success or failure depends 

 in the artificial hybridisation of wheats. Some crosses are difficult, while 

 others are exceptionally easy. As a rule, wheats of different races do not 

 cross so readily as varieties and forms of the same race, but it is occasion- 

 ally observed that pollinations carried out at the same time upon different 

 ears of the same plant are not all equally productive of grain. 



Very slight differences in the state of development of the styles and 



