NOTES AND ABSTEACTS. 



66i 



The authors experimented with wheat seedlings and found that 

 cumarin, vaniUin, and quinone showed a toxic effect which was mani- 

 fested by checking of growth, decreased green weight, and various 

 pathological symptoms. Less nutritive material was removed from the 

 solutions in which plants treated with these poisons were grown. 

 It was found that phosphatic, nitrogenous, and potassic fertilizers were 

 most efficient in counteracting the injurious influences of cumarin, 

 vanillin, and quinone respectively. 



Vanillin and dihydroxy stearic acid are reducing poisons, and were 

 antagonized by fertilizers which stimulate oxidation. Quinone, an 

 'Oxidizing poison, is antagonized by those fertilizers which check 

 ^oxidation. 



Harmful substances occur in soils and may require special ferti- 

 lizers to counteract them. The good done by fertilizers may not be 

 simply by the addition of plant food but by influencing other factors in 

 the soil.— G. F. S. E. 



Polystichum annulare puleherrimum. By F. W. Stansfield 

 {Fern Gaz. i. pp. 274-280; March 1912). — An account of several 

 forms belonging to the variety puleherrimum and the difficulty experi- 

 enced in growing them. — F. J. C. 



Polystichums : Species and Varieties. By 0. B. Green 

 (Fern Gaz. i. pp. 227-231, 262-267; Dec. 1911, March 1912; figs.).— 

 The British species, and especially their varieties, are briefly described, 

 and notes on cultivation given. — F. J. G. 



Potato Culture. By J. H. Shepperd and 0. 0. Churchill 

 {U.S. Agr. Exp. Stn., N. Dakota-, Bull. 90. Jan. 11; illustrated).— 

 This pamphlet emphasizes the value of seed selection, and in addition 

 recommends that potatos be grown intensively, for a poor yield of 

 ,potatos never pays. 



Much useful information is given as to culture, soils and their 

 -preparation, fertilizers, seed, selection, planting, harvesting, storage, 

 >&c., and under " Comimercial uses " we are told that " In 1904-1905 

 (Germany manufactured 76 million odd gallons of denatured alcohol 

 from potatos, using for the purpose 95 million odd bushels. It re- 

 quired 1'26 bushels of potatos for every gallon of alcohol produced." 



C. H. L. 



Potato Leaves, A Bacterial Disease of. By Elizabeth Dale 



[Ann. Bot. xxiv. pp. 133-154; 1912). — A new bacterial disease of 

 potatos is described in this paper. The organism differs both in its 

 reactions and in its effects on the plant from B. solanacearum and 

 B. melanogenes. It forms tubes similar to those found in Legu- 

 minosae and is named B. tuhifex. The author shows that the bacillus 

 attacks the leaves of the potato plant by piercing the cuticle where 

 this is thin enough for it to penetrate. The bacilli form a kind of 

 :zoo'gloea and dissolve the middle lamella of the host plant by means 



