^9oS] CURREXT LITERATURE 2JS 



On p. 62 the "Knight-Danvin law" that "nature abhors perpetual self-fertili- 

 zation" is amended to read, '^nature resists any sudden change in long-estabh'shed 

 conditions." A suggestion having the same import was made some years ago by 

 Hays,s but this seems to have been overlooked by Dr. East. Hays says, *'p)s- 

 sibly Darwix's law would more broadly cover the truth if expressed thus: nature 

 abhors a radical change which would require species to cross in much closer or in 

 much more radical relationship than is their long-established hal)it." 



The last ten pages preceding the summary discuss the technique of maixe 

 breedmg, giving an insight into the great complexity of the prol)lcms to be solved 

 in breeding this crop, owing to the occurrence of fluctuations and numerous 

 elementary species, and the injurious effects of too close inbreeding. The author's 

 experience in maize breeding, as an associate of Hopkins at the lUinois Station, 

 and his continued efforts along similar lines at the Connecticut Station, have 

 thoroughly qualified him to write on this subject, and his discussion will doubtless 

 prove of great value to maize breeders; but the reviewer questions the correctness 

 of the assumption that the isolation of pure strains of maize is the proper aim of 

 those who would secure the greatest possible improvement in this crop. 



It is believed that this excellent bulletin will have such a reception that other 

 stations will follow Dr. East's example in disseminating advanced scientific 

 information.— G. H. Shull. 



The latent life of seeds. — Two rival doctrines have been used heretofore, with 

 equal success, to account for the latent life of seeds. The one holds that life is 

 completely suspended, all the exchanges, both of matter and of energ>', being 

 arrested. The other holds that the phenomena of metabolism are greatly dim- 

 mished, but that they are never entirely suppressed. Both of these theories have 

 been supported by experimental evidence, and the question has called forth a ver>' 

 large number of investigations. These antagonistic views have led Becquerel 

 to a further study,^ with the idea that the previous conflicting results depended 

 ujx)n neglected properties of the integuments. He has demonstrated the impcr- 

 nieability for gases of the integuments of seeds of a considerable number of 

 species; and it seems Gola^ simultaneously had discovered impermeability for 

 water to be a common character. 



These facts make it necessary to go over previous experiments, perforating 

 the integuments or removing them. Seeds which resist the action of alcohol, 

 ether, and chloroform, when their integuments are intact, succumb when these 

 agents are brought into actual contact with the embrj'o. But low temperatures, 

 even to — 210°, do not have any appreciable effect on germination if the protoplasm 

 has already undergone thorough desiccation. The existence of gaseous exchanges, 



5 Hays, W. M., Plant breeding. U. S. Division of Physiology- and Pathologv-, 

 Bull. No. 29. pp. 72. figs, 21. 1901. (See pp. 38, 39.) 



^Becquerel, Paul, Recherches sur la vie latente de graines. Ann. Sci. Xat. 

 Bot. IX. 5:193-320. 1907. 



^As cited bj^ Becquerel: Gola, J., Memoire sur la physiologie [in another 

 place, Recherches sur] des teguments des graines. Acad. [Sci.] Turin. 1905. 



