NOTES AND ABSTRACTS. 



621 



(3) Keep the soil sweet and give lime frequently. 



(4) If club-root is discovered, raise the plants and burn those 

 affected. 



(5) Arrange rotation that crucifers will not succeed one another. 



(6) Keep down cruciferous weeds, e.g. Shepherd's Purse and such 

 like.— H. E. D. 



Club-poot disease in the Cabbagre family. Anon. {Gard., 



March 18, 1911, p. 126). — The writer had to deal with the cultivation 

 ■of winter greens on ground where the soil had become sour and club- 

 root disease was prevalent. He dug in lime and a peck of salt to each 

 square rod every spring, and in two years the plants grown were free 

 from disease and grew freely in dry seasons. — H. R. D. 



Coceidae of Audubon Park, New Orleans. By T. 0. Barber 

 {Jour. Econ. Entom., iii. 5; pp. 420-425; Oct. 1910).— A hst of 

 ithirty-four scale insects with their hosts. — F. J. C. 



Coceidae of Boulder County, Colorado. By T. D. A. Cockerell 

 {Jour. Econ. Entom., iii. 5; pp. 425-430; Oct. 1910).— A Hst with 

 aotes of scale insects of a portion of Colorado. Interesting notes of 



' liistribution with plants are included. — F. J. G. 



it 



Corn, Improvement in. By H. K. Hayes and E. M. East 

 U.S.A. Exp. Stn., Gonnecticut, Bull. 168, June 1911; plates). — 

 uogically directed efforts to improve the general field crops of the 

 'Jnited States may be said to have begun with the introduction of 

 /ilmorin's isolation principle. In applying this principle to Indian 

 om breeding a large number of selected ears are grown in such a way 

 hat the yield of each ear may be compared with that of every other 

 •ar, and the average character of a plant's progeny is taken as an index 

 3 that particular plant's productiveness. Continued selection by this 

 lethod yielded very promising results during the early years of its 

 pplication, but the later generations failed to fulfil this promise. This 

 ulletin considers the reasons for this failure, and points out the pos- 

 - bilities which lie open in other methods, based on the fuller under- 

 ■•^^lianding which we now possess of the underlying principles concerned. 

 ■'^1 The process of fertilization acts in two very different ways : first 

 ^irough a union of the hereditary characters possessed by the parents, 

 ' id second through a stimulation to the cell-division necessary for 

 ■ Drmal development; and since the re-discovery of Mendel's law in 

 )00 our knowledge of this first process — the transmission of parental 

 " laracters — has been greatly increased. It has been clearly proved that 

 plant or animal does not transmit its characteristics as if the entire 

 ■ganism were the unit, but rather that its various characters are 

 herited separately. Such characters are known as " unit characters," 

 .id if a plant breeds true for one of these characters its unit " must 

 ■• '^'Wive been received from both of the parents, and is said to be in a 



