AGBICULTURAL BOTANY. 321 



to the maturing ovules. In some of the plants, however, capsules were formed, 

 and an examination made of 650 showed seed in a small proportion of them. 

 One hundred capsules were found to contain nearly 900 seed, 26 per cent of 

 which germinated. This seems to indicate that the Fi hybrids resulting from 

 the crossing of N. sylvestris and N. tahacum should be included among those 

 hybrids which are only partially self-sterile. 



The bearing- of teratological development in Nicotiana on theories of 

 heredity, O. E. White (Amcr. Nat., 47 (1913), No. 556, pp. 206-228, figs. 2).— 

 A preliminary report is given of a study of the abnormal development of 

 Nicotiana considered from the standpoint of pedigree culture and cytological 

 methods. Two strains of N. tahacum were investigated, one of which was a 

 £.}>ort from the other. The sport is shown to differ from the normal form in 

 the possession of a unit character due to one Mendelian factor. When it is 

 crossed with the normal form there results in Fj a simple Mendelian ratio 

 of 3 : 1. 



The author concludes that the facts obtained by his investigations warrant 

 the belief that some agent is at work on the internal structure as well as on 

 the so-called external that is of such a nature as to produce abnormalities in 

 cell structure as well as in cell complexes or plant organs. This raises a 

 question as to the significance of chromosomes in inheritance. From a study 

 of chromosomes in relation to Mendelian factors and as a basis of inheritance, 

 he concludes that while the phenomena of segregation may be capable of inter- 

 pretation on a morphological basis, the gene for fasciation appears to lie 

 deeper in sporogenesis than chromosomes. The abnormal character develop- 

 ment, it is believed, is most easily interpreted from a physiological standpoint. 



Tetraploid mutants and chromosome m.echamsms, R. R. Gates {Biol. 

 Ccntbl., S3 (1913), No. S, pp. 11 3-1 50, figs. 7).— The author reports a study of 

 gigantism and tetraploidy in CEnothera from a comparative standpoint made 

 with a view to securing a better understanding of their relation to evolu- 

 tion. In addition to the gigas type described by de Vries, studies were made 

 of other giant forms that have arisen independently in Italy and Sweden. 

 Statistical studies were made of the pollen grains, and the chromosomes of 

 the different races were compared. 



The author concludes that some of the characters of CEnothera are Men- 

 delian in their behavior after they have arisen, but that such combinations 

 are not always adequate to account for their original appearance. He agrees 

 with Nilsson that many of the mutant differences are due to changes which 

 are fundamentally quantitative. Many of the size differences in the races vrith 

 higher chromosome numbers are also probably due to differences in the number 

 of chromosomes in their cells. 



A bibliography of the subject is given. 



Herbag-e studies. — II, Variation in Lotus corniculatus and Trifolium re- 

 pens (cyanophoric plants), H. E. and E. F. Akmstrong and E. Hoeton {Proc. 

 Roy. Soc. [London-\, Ser. B, 86 (1918), No. B 587, pp. 262-269).— In continua- 

 tion of work previously noted (E. S. R., 27, p. 30), the authors extended their 

 studies of L. corniculatus. As a result it is claimed that while the normal 

 form of this plant met with in southern parts of Great Britain contains both 

 a cyanophoric glucosid and the correlated enzyms, in Scotland and also in 

 Norway a form prevails which is rich in enzym but contains mere traces of 

 the glucosid, and that a third form of this clover exists in which the amount 

 of enzym is also very small. It is thought that to these two correlated factors, 

 glucosid and enzym, a third is to be added, probably one influencing concen- 

 tration. The suggestion is made that by continuing work in this direction 

 some light may be obtained on the general problem of variation. 



