336 EXPERIMENT STATION EECORD. 



nutansXH. disUchuni nudum, H. distichum erectumXH. distichum nudum, 

 H. coeleste trifurcatumXH. distichmn nutans, H. coeleste trifurcatumXH. 

 zeocriton, and H. coeleste trifurcatumXH. steiulelii. It is pointed out that tlie 

 rules of heredity discovered by Naudin have si:)ecial application in crossing dif- 

 ferent species and govern the character of abortiveness in such crosses. See also 

 another article abstracted on page 328 of this issue. 



Behavior, under cultural conditions, of species of cacti known as Opuntia, 

 D. Griffiths (U. 8. Dept. Agr. Bui. 31, pp. 24, pis. 8, fig. i).— This bulletin 

 records observations taken at Brownsville and San Antonio, Tex., and Chico, 

 Cal., on between 600 and 1,500 varieties of prickly pear and cane cacti. Notes 

 and discussions include spine variation, adaptability to conditions, excessive 

 development of spicules, locality variations, effect of housing, longevity, effect of 

 low temperatures, coloration, jiroliferation of fruit, habits of the plants, and 

 moisture requirements. 



It is noted that " all forms thrive best when the moisture supply is low during 

 the dormant season. Wherever tried, some species or form native to the region 

 has proved more productive than introduced forms. . . . Considering the suc- 

 culence of the plants, their power of recovery from the effect of low temperatures 

 is remarkable. Large limbs which hang limp beside the plants will often regain 

 their normal position upon the advent of growing weather, provided they are not 

 disturbed while the weather is cold. . . . Proliferation of fruit is not necessar- 

 ily a specific characteristic but may be brought on by extraneous conditions. If 

 this habit could be induced in the economic forms their value for forage would 

 be decidedly increased. In all of the larger species especially, the plants grown 

 from cuttings and those grown from seed present a very different appearance; 

 the latter are treelike and the former are headed on the ground without distinct 

 stems." 



The result of selecting fluctuating variations, F. M. Surface (IV. Conf. 

 Inteniat. Genetique Paris, Compf. Rend, et Raps., 1911, pp. 222-236) .—The 

 author gives the results obtained at the Illinois Experiment Station in the 

 production of high protein, low protein, high oil, and low oil varieties of com 

 as previously noted (E. S. R., 20, p. 531). 



Inheritance of waxy endosperm in hybrids of Chinese maize, G. N. Collins 

 and J. H. Kempton {IV. Conf. Internat. Genetique Paris, Compt. Rend, et Raps., 

 1911, pp. 347-357). — More detailed results are given of a series of crosses be- 

 tween Chinese corn with waxy endosperm and American varieties with horny 

 endosperm, previously noted (E. S. R., 29, p. 35). "For the whole series of 

 crosses the percentage of waxy seeds was 23.1, a deviation from the expected 

 25 of over 9 times the probable, error. 



" Where a Chinese variety with colorless aleurone was crossed with an Ameri- 

 can variety with colored aleurone, the second generation showed a coherence or 

 positive correlation between waxy endosperm and colorless aleurone. Where the 

 Chinese parent had a colored aleurone and the American parent was white, the 

 positive correlation was between the opposite characters, waxy endosperm and 

 colored aleurone. These results are interpreted as showing a definite tendency 

 for characters that are associated in the parents to appear together in the 

 later generations of the hybrids. Similar examples of coherence have been 

 reported in the other crop plants, though this seems to be the first instance 

 where the correlation is reversible." 



See also a previous note by Collins (E. S. R., 29, p. 633). 



Corn improvement (Arkansas 8ta. Bui. 115, pp. 549-574, figs. 14). — The 

 first portion of this bulletin, by C. V. Ruzek. discusses the buying, selection, 

 and storing of seed corn ; describes methods of germination tests : and points 

 out good and poor characteristics of ears and kernels. The second portion, by 



