3G EXPERIMENT STATION RECORD. 



present in the culture medium. For tlie principal cereals, such as rye, barlej', 

 and wheat, the proportion of 1 : 1 gave the best results in sand cultures, while 

 an increase or decrease in the ratio depreciated the total production by from 40 

 to 60 per cent. The lime factor was found to influence grain production more 

 than that of straw, and an overabundance of lime depreciated grain, while 

 magnesium in excess reduced the total straw production. In water cultures a 

 ratio of 20 parts magnesium to 1 of lime killed all rye plants in 50 days, and a 

 ratio of 10:1 checked growth to a considerable extent. The influence of the 

 varying lime factor was least apparent in the early stages of growth but became 

 very pronounced during the flowering period and at maturity. 



A superabundance of magnesium had a drying effect on the leaf tips and 

 growing points. In sand cultures there was often a recovery, while in water 

 cultures growth stopped and the plants died. Where there was a great defi- 

 ciency of lime the plants died from above downward, while if magnesium was 

 wanting death occurred from below upward. The root development was gen- 

 erally stimulated by a favorable lime factor. The presence and character of 

 the root hairs was found to be influenced by the ratio of lime to magnesium, a 

 favorable lime factor resulting in well developed long root hairs while too 

 much lime caused the production of short stunted root hairs but without any 

 pathological ajipearance. An overproiiortion of magnesium checked the growth 

 of root hairs arid produced a pathological appearance. 



The author claims that the theories of Loew relating to the function of lime 

 in the nuclear development and of Willstatter regarding the lack of magnesium 

 in chlorophyll production are confirmed by his experiments. He calls attention 

 to a number of unfavorable factors that may be the cause of wrong inference^j 

 in pot experiments, and states that his investigations show that the strongest 

 and best developed plants are the ones which exhibit the greatest differences in 

 the effect of the lime factor. 



The variation in the color of seeds and its practical application, G. Ritteb 

 {Ber. K. Lehranst. Wviii, Ohst ii. (Jaiicnhau Gcisciiliciiu, WJO, pp. l3Ji, 135). — 

 Attention is called to investigations that have been made regarding the varia- 

 tion in color of seeds, particularly those of leguminous plants. A'ariation in 

 color is held by the author to be due to the conditions under which ripening 

 takes place, and a change in the color and weight of the seed from the normal 

 condition is attributed to unfavorable conditions during ripening. The heaviest 

 seed are those which are normally matured, and there is said to be a correla- 

 tion between the color of the seed, their germination, the growth of the plants, 

 and resistance to disease. 



Inheritance of the " eye " in Vigna, W. J. Spillman {Amer. Nat., Jf5 (1911), 

 No. 537, pp. 513-523, fig. 1 ) . — An account is given of the inheritance of color in 

 cowpeas, the study having been made of a large number of crosses. The Fi 

 generation in all cases reported was solid in color, while the F2 generation gave 

 ranges of color from pure white to completely pigmented. The ratios of segre- 

 gation are given and various hypotheses are proposed to account for their 

 behavior. 



Long versus short periods of transpiration in plants used as indicators 

 of soil fertility, F. S. Harris (Proc. Amor. ."^oc. Agron., 2 (1910), pp. 93-102).— 

 On account of the wide use of the measure of transpiration of plants gi'own 

 for short periods as an indication of the fertility of the soil, the author has 

 carried on an investigation with wheat plants. 



The results indicate that with different treatments plants do not continue to 

 transpire the same relative amounts during all the periods of growth. Where 

 the transpirations for a limited period are compared, erroneous conclusions 



