Varietäten, Descendenz, Hybriden. 133 



lucral Whorl of Hibiscus. (ßiometrika VIII. pp. 52—65. 5 

 text-figures. 1911.) 



A collection of statistics as regard the number of involucral 

 bracts and the number of ovules and seeds in six species of 

 Hibiscus, arranged in correlation tables. Over 65,000 countings were 

 raade in all, and it is concluded that "the correlations between 

 number of bracts and number of ovules or seeds are sometimes 

 statisticall}^ significant with regard to their probable errors, but 

 are uniformly of such low magnitude that no practical biological 

 importance is to be attached to them". 



R. H. Compton (Cambridge). 



Hill, A. W„ The History of Primula obconica Ha nee, under 

 Cultivation, with sorae Remarks on the History of 

 Primula sinensis Sat. (Journ. of Genetics, II. N" 1. pp. 1-20. 

 pl. 1—2. (coloured) 1912.) 



Primula obconica, introduced into England froni China by 

 Maries in 1879, has since that date yielded a large number of 

 horticultural varieties. The historical records of the appearance of 

 the most important new features. such as the white, rose and 

 violet-blue colour of the flowers, different types of ,,eye", increased 

 size of flowers, fimbriation of petals, doubling of the corolla, are 

 fuUy cited. Despite repeated attempts at hybridisation, it appears 

 that it is improbable that hybrids of P. obconica with other species 

 have ever been produced; the results always suggesting accidental 

 self-pollination (or perhaps stimulated apogam}'^). The horticultural 

 development appears to be due to selective processes. 



R. H. Compton (Cambridge). 



Howard, A. and G. L. C. Howard. Studies in Indian Fibre 

 Plauts. N^ 1. On wo varieties of Sann. Crotalaria juncea L. 

 (Mem. Dept. Agric. India. Bot. Ser. Vol. III. W 3. pp. 177—189. 

 3 pl. 1910.) 



Examination and pure line cultures of Sann Hemp at Pusa 

 has shown the existence of two distinct varieties of this important 

 tibre-plant. A local variety differs from the Jubbulpore plant in 

 shorter stature, smaller seed and slower germination, while it is 

 also comparatively late-maturing. It was found that, in practical 

 value, the Jubbulpore variety yielded a superior fibre and was more 

 valuable as a green manure. " S. E. Chandler. 



Jones, W. N., Species Hybrids of Digitalis. (Journ. of Gene- 

 tics II. pp. 71— 8<S. pl. 3—5. fig. 1—45. 1912.) 



A detailed comparative description, fully illuscrated with 

 coloured and monochrome photographs and line drawings, of 

 Digitalis purpurea, D. grandiflora and their two reciprocal F 1 

 hybrids. It was 'found much easier to effect the cross in which 

 D. purpurea is the seed-parent. The characters are tabulated under 

 sixteen headings, and it is concluded that in general the expression 

 of any character in the hybrids is intermediate between its expres- 

 sion in the two parents, the reciprocals differing from one another 

 in that each shows a greater reserablance to the seed-parent. In 



