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Wallace ; Desert Scenes in Zacatecas, an illustrated paper by 

 Professor J. E. Kirkwood describing the 400,000 square miles 

 of country south of the Rio Grande ; and a continued paper on 

 The Argument for Organic Evolution before " The Origin of 

 Species," by Professor Arthur O. Lovejoy. 



Mention has not been previously made of the description of a 

 simple chemical device illustrating Mendelian inheritance, which 

 was printed in the Plant World for July, 1909. A litmus solu- 

 tion, sodium hydroxide or aqua ammonia, and hydrochloric acid 

 are used to illustrate : " the more common type of Mendelian 

 inheritance, that in which presence is dominant over absence" ; 

 "the dominance of absence over presence" ; and "the equiva- 

 lence of reciprocal crosses, regardless of the fact that ^^^ and 

 sperm differ much in size." 



The September Popular' Science Monthly includes a short article 

 by Luther Burbank on Another Mode of Species Formation. 

 In this article Mr. Burbank calls attention to the fact that those 

 who formerly practised crossing to secure a mongrel which might 

 or might not surpass its parents did not realize that " crossing ivas 

 only the first step and that selection from the nwnerons variations 

 secured in the second and a few succeeding generations zvas the 

 real ivork of the new plant creation " work. Mr. Burbank gives an 

 interesting list of hybrids, some formed under cultivation, and 

 some found in a wild state, which come true to seed. 



A gigantic irrigation scheme is being planned for the rehabili- 

 tation of Mesopotamia upon such a scale that 3,000,000 acres of 

 the best land in that country will be provided with water. The 

 plans consist of providing a means of escape for the flood waters 

 of the Euphrates ; and the Tigris, the Euphrates, and the Akkar 

 Kuf Lake will form part of a controlled system of canals whereby 

 the pernicious silt is to be separated, floods are to be prevented, 

 and wheat-bearing land is to be supplied with water. It is esti- 

 mated that the cultivated area will be doubled, the crop of wheat 



