NOTES AND ABSTRACTS. 463 



gummosis of Pru7ius and Citrus are indistinguishable maladies, and 

 that they are identical in histological development and causal relation- 

 ships. The malady is due to hydrolysis of the walls of the embryonic 

 wood-cells, which develop into susceptible tissue. The dissolution of 

 the cell-walls begins in the secondary lamella and almost coincidently 

 ill the primary membrane, the dissolution of the third lamella proceeds 

 centripetally. The cell- contents are a't no time actively concerned in 

 gum formation, neither does starch play any role. Gummosis develops 

 autogenously and is induced by all manner of traumatisms, provided 

 they act directly or indirectly as growth stimulants on the cambium. 

 The cambium must be actively growing and an abundant supply of 

 water must be available at the roots. 



Squamosis and Exanthema are diseases confined to America and 

 need not be referred to in detail here. — A. D. C. 



Inheritance in Maize. By E. M. East and K. K. Nayes 

 (U.S.A. Exp. Stn., Conn., Bull. 16; 1^11; MO pp., 25 plates).— 

 The names of the authors give sufficient assurance that the experi- 

 ments dealt with in this work have been carried out with the most 

 minute care, and a description of methods used is therefore un- 

 necessary. 



After discussion of the material used, its suitability for genetic 

 research, and a description of the varieties under notice, the authors 

 3ass to inheritance of endosperm characters (Part 11.). 



Starchiness and N on-Star chines s. — Starchy individuals, whether 

 starch was in corneous or soft condition, were dominant when crossed 

 vith non-starchy {i.e. " sugar maize "), and the usual segregation 

 )ccurred. 



The difference of the two starches was studied chemically, and 

 itarchy grains were found to produce their starch on ripening at a 

 teady rate, while in the non-starchy races an actual breaking down 

 I endosperm materials into cane-sugars and various hexoses occurs. 



Yellow and Non-Yellow Endosperm. — The yellow colour was found 

 0 be due to two pigments which do not seem to belong to the lipo- 

 hrome series, but are probably to be classed as anthochlorins. Fur- 

 ler experiment is to be made on this subject. 



Yellow proved dominant, though in F2 certain peculiarities occurred, 

 at the extracted whites proved pure. 



Purple and Non-Purple Aleurone Cells. — There ard two pigments 

 iving a purple colour, and though rough chemical tests show differ- 

 ices, they are probably to be considered as different stages of 

 ; iidation of the same colour base. A large amount of data is pre- 

 inted of the greatest interest, and the conclusion is reached that 

 irple aleurone colour behaves as a normal Mendelian character in 

 heritance. 



Xenia. — The authors, referring to Guignard's discovery of the non- 

 aternat character of the endosperm, state that the old meaning ol 

 e word must of course be given up, and in their experiments the 



