520 EXPERIMENT STATION RECORD. [Vol. 40 



Effect of bog and swamp waters on swelling in plants and in biocolloids, 

 D. T. MacDouual (Plant World, 11 [1918), No. .*,. pp. 88-99, fig. l).— This 

 work was undertaken primarily to determine the principal factors In plant 

 growth, but extended t<> a general consideration of swelling in protoplasm as 

 affected by its own composition and by various solutions, it was baaed upon 

 the assumption (and Its experimental justification) that the materials which 

 make up the protoplasm of a plant, if combined in the form of an elastic gel, 

 would show for the resulting mass water relations similar to those of the plant 

 A mixture'of 80 to 90 parts of agar and 20 to 1<> parts of albumin, gelatin, or 

 albuminous derivatives, impregnated with the nutrient salts In proportions 

 decreasing to the vanishing point, stimulates the swelling action of the proto- 

 plasm Of stems and roots of the various plants tested, Various factors may 

 Influence the amount and nature of the swelling, whlcb may then-fore offer 

 suggestions as to the character of the solutions in which it occurs. 



The general method of preparing the biocolloids baa been described in previ- 

 ous papers (E. S. It.. .''.7. p. 821 : 38, p. 729). Bog and swamp waters of typical 

 constitution were employed in tests with disks of Opuntia discaia, which was 

 also tested In nutrient and In simple solutions. It Is stated that living matter 

 swells In solutions |n f|| ( . same manner as do biocolloids consisting of salted 

 mixtures of varying proportions of agar and protein or albuminous derivative 

 The swelling of biocolloids and that of living and dried sections of plants In 



distilled water, bog water, and a calcium solution of th.' B8J DCentratlon 



as tie' bog wafer, are said to he practically equal. Swamp water was found 

 to affect absorption and swelling as does an equivalent solution of calcium 

 sulphate. Swelling and absorption are retarded l>y swamp water In salted 

 biocolloids and in sections of plants having a Urge proportion of pentosans 

 and a low protein content. Biocolloids having a high protein and salt content, 

 on the other hand, show an enhanced absorption In swamp water. The infer- 

 ence Is that plants of similar constitution would carry on absorption readily and 

 thrive in swamp w atera 



A new three-salt nutrient solution for plant culture. 1".. 1". LrvuiOC 

 and w. EL ToTrmoHAii (Amer, Jour. BoL, :> (/.''/.s>. No. 7. /-/,. STi 3#), The 



authors have taken up the problem which has been made tin- BUbJect of a pre 



llminary and a fuller report by Shiva (E, S. u . 34, p. 333; 36, p 328), employ- 

 ing a second of the sis logically possible combinations "f salts containing the 



•lit 1 : 1 1 Ions ('a, K, Ml'. N< >i, S< >.. and !'<>,. in the form of potassium nitrate, 



magnesium sulphate, and monocalclum phosphate. This preliminary investi- 

 gation Involved, however, only 12 sets of salt proportions as opposed to the 36 



>ets employed by Shlve, the total concentration being also in this work about 



1.75 atmospheres. Wheat of the same variety and technique of the same sort 

 as employed by Shlve were used In this work, the culture period extending from 

 Max L5 to .In lie 2. 



The data obtained, as presented and discussed, are considered as showing 



the optimum solutions here employed to he as good as. or hotter than, the solu- 

 tion found by Shlve to he optimal, though both are said to give some evldea 

 of magnesium poisoning in case of wheat plants. It is thought that some evi- 

 dences of poisoning may be expected whenever maximum dry-Weight xaluos are 

 obtained with young wheat plants, if the transpiration rate is not too low. 



The progress of knowledge of the relations between nutrient solutions and 

 plant growth is thought to suggest strongl] that, after all. the physiological 

 properties of a solution are not determined simply hy atomic, Ionic, or molecular 

 proporl ions. 



Organic plant poisons. — II. Phenols, W. V,. Hhimiiivv i \nn. Boi. [Lotlr 

 ilnn]. 32 (1'JIS), \„. 126, pp. J"..' 878, /'";/*. 18).— The author has carried for- 



