NOTES AND ABSTRACTS. 



to the action of gravity, though not so much so as the Coleoptile. The 

 reader must, however, be referred to the original for details of this 

 research. 



The author also tested the effect of aluminium salts in removing 

 starch from plants, but comes to the conclusion that this method cannot 

 be used as a control of the statolith theory. — G. F. S. E. 



Coastal Subsidence and Buried Forests. By Douglas Wilson 

 Johnson {Bot. Gaz. Dec. 1913, pp. 449-468 ; with nine figs.). — The 

 author shows how the formation or washing away of a barrier reef 

 may lead to false conclusions as to elevation or subsidence of the 

 coast-line. — G. F. S. E. 



Codling Moth, The Calliephialtes Parasite of. By R. A. 



Cushman (Jour. Agr. Research, i. p. 211-238, Dec. 1913 ; pL). — The 

 life-history and habits of this insect, Calliephialtes messor, parasitic 

 on the codhng moth, are described. — F. J. C. 



Colloidal Metals on Spirogyra, Effect of. By W. D. Hoyt 

 [Bot. Gaz. Ivii. pp. 193-212, March 1914) ; with 4 figures. — Solutions of 

 90 and 96 parts in amilHon of colloidal gold and platinum respectively 

 were almost without effect, whilst even "00225 parts in a million of 

 colloidal silver were injurious, and anything above -045 parts in a million 

 proved fatal. 



Low concentrations of the first two mentioned metals (and in a 

 less degree of colloidal silver) partially prevented injury to Spirogyra 

 filaments by NaOH. 



The author also investigated the gelatinous swelling of the outer 

 cell-walls of Spirogyra produced by colloidal gold or platinum and 

 NaOH. 



Spirogyra filaments of the same culture, but grown in different 

 media, reacted differently in various toxic solutions. — G. F. S. E. 



Colorado Potato Beetle, Zinc Arsenite and Lead Chromate as 

 Remedies against. By F. A. Johnson [U.S.A. Dep. Agr., Bur. of 

 Entom., Biill. 109, pt. v. 1912). — Lead chromate, either alone or 

 mixed with fungicide, gave very poor results, while zinc arsenite com- 

 pares very favourably with lead arseniate against the above pest. 



The best results with zinc arsenite were obtained with a solution 

 of 2 lb. to 50 gallons of water, and the author suggests that even 

 higher strengths may be used with safety. — C. P. C. 



Cost of Production, The Determination of. By C. S. Orwin 

 [Jour. Bd. Agr., vol. xxi. No. 3, pp. 193-201). — The great importance 

 and need of investigations leading to the determination of the cost 

 of the production of agricultural produce is dealt with at some length. 

 The necessity for uniformity of method, and the uselessness of results 

 arrived at by differing methods, are pointed out. It is also clearly 

 shown that when a home-grown product (e.g. hay or straw) is consumed 



