MISSOURI BOTANICAL GARDEN BULLETIN 13 



week of growth are materially dwarfed in further develop- 

 ment No organic nitrogenous nutrients or combinations of 

 nutrients have thus far been found which will fully compen- 

 sate for the food reserve naturally provided by the cotyledon. 

 It is suggested that possibly a specific vitamine is involved in 

 the effectiveness of the cotyledon. 



Duggar, B. M. (Ann. Mo. Bot. Gard. 7:306-328) has ex- 

 perimented with the use of relatively insoluble salts in bal- 

 anced nutrient solutions for certain seed plants— including 

 corn and wheat in the data reported. It is pointed out that 

 combinations of such salts are interesting (1) because of the 

 constant concentration of most of the ions representing the 

 necessary elements, and (2) because no renewal of solutions 

 is required from time to time. It was found necessary to em- 

 ploy a soluble nitrate. Highly favorable yields are reported 

 for several combinations involving two or more relatively in- 

 soluble salts, and further work is projected. 



Karrer, Joanne L. and R. W. Webb. (Ann. Mo. Bot. Gard. 

 7:299-305). For the benefit of subsequent workers complete 

 titration curves of certain liquid culture media for the fungi 

 have been worked out. These curves cover the entire range 

 of acidity and alkalinity within which the common mould 

 fungi ordinarily grow. 



Zeller, S. M. (Ann. Mo. Bot, Gard. 7:51-73). Tins paper 

 reports in extensive tables and curves the moisture content 

 for sap- and heart-wood of both longleaf and shortieaf pine 

 at various humidities and at 25° C. Attention is again drawn 

 to the fact that although highly resinous samples exhibit a 

 strong water-proofing effect, still the unequal distribution of 

 resin is a factor in the weakness of wood in respect to decay 

 by fungi. The fungus Lenzites saepiaria will germinate on 

 wood shavings at relative humidities about 63 per cent, and 

 is accelerated when the humidity is high enough to maintain 

 fiber saturation. 



HERBARIUM 



The herbarium has had a normal growth during the year 

 by the addition of new material from various parts of the 

 world. Particular attention, however, has been given to aug- 

 menting the collections representing the flora of the central 

 and western parts of the United States. The new steel cases 

 which were installed late in 1919 have relieved temporarily the 

 congestion in that part of the herbarium which includes the 

 monocotyledonous plants. Thus, it has been possible to more 

 thoroughly organize several of the families in this series which 



