AGRICULTURAL BOTANY, 529 



Ciossypium, the author decides that the Americau upland cotton should be re- 

 ferred to G. siamense and not to (L hirsutitiii or G. herbacciim, as is commonly 

 reported. The growth characters of the Americau upland cotton and the 

 species described from Siam are quite similar, and the author thinks that it is 

 probable that the upland cotton was introduced from eastern Asia to the botanic 

 gardens and afterwards to cultivation in America. 



Some cytolog'ical aspects of cotton breeding, L. Balls (Amer. Breeders' 

 Assoc. [Pruc], 5 (1909), iJi). 16-28, dyms. 2). — The author discusses the connec- 

 tion between cytology and heredity, and gives an account of some of his investi- 

 gations on the breedhig of cotton. 



A list is given of about two dozen allelomorphic pairs in cotton, which, al- 

 though these do not by any means include all the possibilities of inheritance in 

 cotton crosses, indicate the possibility of making over 600 pure strains. There 

 is also a discussion of the development of the lint on the cotton seed. In con- 

 clusion the author states that he has found that the vast majority of crosses 

 in a cotton crop are heterozygous in several characters, and that the amount 

 of crossing which takes place between cotton i)lants growing in a field pro- 

 ducing this heterozygous condition ranges from .") to 25 per cent. As a result, 

 no i>edigrec can be considered as evidence for or against any law of heredity 

 unless this natural crossing has been recognized or excluded. Recognizing this 

 tendency to heterozygosity, the author claims that the so-called easy variation 

 of cotton is not a fluctuation, but is merely a difference of rigid gametic con- 

 stitution, with some small amount of fluctuation. So far as has been investi- 

 gated, Mendel's law applies to all characters of the cotton plant. 



Seeds and plants imported during' the period from. January 1 to March 31, 

 1909. Inventory No. 18 ( /'. .s'. r)< i)i. Ayr., Bur. Plant Jnilits. Bill. 162, pp. 

 73). — ^Thls gives a list, together with notes upon the economic value, of the seeds 

 and plants secured between January 1 and March 31, 1909, the number of items 

 amounting to 7151. It is largely made up of collections forwarded by N. E. 

 Hansen, of the South Dakota Station, while acting as an agricultui-nl explorer 

 for the Department. 



Vitality of pine seeds and the delayed opening of cones, W. C. Cokeb 

 (Amer. Aat., J,3 {1909), No. 515, pp. 6'7'7-()8/).— Attention is called to the reten- 

 tion of the cones by the knob-cone and Monterey pines, the author stating that 

 the cones are frequently retained unopened on trees that are 30 or more years 

 old. As all cones are borne on new growth, the peduncles of the cones must be 

 broken loose from their connection with the wood, so as to allow the cones to be 

 pushed out by the annual growth. The cones that remain on the surface of the 

 trunk are said to have no organic connection with the tree, and they do not shed 

 their seeds until the tree or branch that bears them dies. 



This condition of some of the California pines led the author to investigate 

 the vitality of the seeds of the common Finus serotiita of South Carolina, which 

 holds its cones unopened for several years. Specimens of unopened cones 10 or 

 more years old were obtained, and the seeds collected and their germination 

 determined. From the tabular statement presented the germination of the 

 different lots was found to fluctuate, but seeds as old as 14 years gave consider- 

 able germination. 



The effect of different solar radiations on jplants, C. Flammarion (Bui. 

 Mens. Off. Renscig. Ayr. [Paris], S {1909), No. ,S, pp. 1111-1119).— X brief ac- 

 count is given of investigations with beans, x^eas, and leeks, in which the effect 

 of different coloi-ed screens on the nitrogen content of the plants is shown. 



In general it was found that under the colored glass the increase in nitrogen 

 is more rapid than under the clear glass. This increase seems to be greatest 



