324 EXPERIMENT STATION RECORD. [Vol. 40 



Mitochondria arc stated to present well defined characters which are in 

 most cases easily studied, especially in certain animal cells. 



Generally the chondriome of the vegetable cell Is represented very early by 

 granular mitochondria. In the embryonic cells, some of those elements are 

 changed into chondriocontes which develop into plastids, while others usually 

 remain as granular mitochondria, performing other functions or simply perpetu- 

 ating the chondriome. 



The relation of" the plant to the reaction of the nutrient solution, D. R. 

 IIoaot.and (Science, n. ser., 48 (1918), Ao. 12^3, pp. >)■ — I" * previous 



paper (E. S. R., 38, p. 736), the author described the effect of the hydrogen 

 and the hydroxy! ion concentration on the growth of barley seedlings. The 

 experiments with barley seedlings are said t<> have indicated a strong tendency 

 on tlie part <»f the plant to change the reaction of various potassium phospl 

 solutions in the direction of neutrality. The work has been extended to other 

 solutions. Including complete nutrient solutions, and observations have beeu 

 made at all stages in the growth cycle of the barley plant. The experiments 

 were carried out in sand and water cultures, and in addition to barley plants 

 several varieties of beans were us 



In every instance, nutrient solutions of an acid reaction reached an approxi- 

 mately neutral reaction after contact with the plant roots tor varying peri< 

 of time The neutral solutions remained constant in reaction throughout the 

 nil ire period. Chemical analyses of the BOlutiona indicated that the chai 

 in reaction was the result of selective absorption of the various phosphoric 

 acid anions, accompanied by a removal of positive ions. A mar; mlatory 



absorption Is said to have been apparent. 



Considering the nature of acid soils and their relation to crop growth, the 

 author stales that it is often assumed that most agricultural plants require a 

 slightly alkaline reaction in the boIL Previous work has shown that a reaction 



Of pll •") is in no way inhihitive t • the growth of barley s liings. This point 



has been further I ati d with the use of several varieties of beans in sand 



cultures. The solutions were changed with sufficient frequency to maintain 

 constantly an acid reaction, imt no injury was apparent Observations are 

 given on some California peal SOUS, which wife found to be decidedly add, and, 

 where other inhibiting factors were absent, first-class crops of barley, oats, 

 beans, potatoes, onions, corn, and asparagus were produced. It is claimed 

 that in these s.iils the acid reaction did not interfere with the growth of CTO 

 nor the formation of nitrates. 



The value of certain nutritive elements in the development of the oat 

 plant, J. G. Dickson (Amer. -lour. lint., r, (1918), No. 6, 1 '.';. tins, fi).— 



Experiments carried out during the growing seasons of 1915 1917, and planned 

 to show the effects of some of the essential nutritive elements on the develop- 

 ment and composition of plants when other physico-chemical Factors, such as 

 unequal Osmotic pressure ami the addition of new chemical elements, were 

 controlled as far as possible, are reported The author, employing with it* 

 sativa aristata a modified Knop's solution, found that the general development 

 of the plants studied was most severely affected by a deficiency of phosphorus 

 or of nitrogen, these preventing the stooling of the plants. 



A deficiency of calcium or magnesium Increases vigor of growth but lengthens 

 the period of development, which Is shortened by a deficiency of potassium, ph 

 phoms, or nitrogen, (".rain production is lowered by a deficiency of magnesium, 

 calcium, potassium, phosphorus, or nitrogen. The rati.' of grain to straw is 

 decreased by a deficiency in magnesium or calcium and is increased by a 

 deficiency in potassium, phosphorus, or nitrogen. The water requirement is 

 decreased by a deficiency in magnesium, Slightly increased by a deficiency in 



