HORTICULTURE. 739 



I. A basis for selection of desirable seed for breeding for improvement of 

 nitrogen content. — Following a summary of available data, the author reports 

 (lata based on analyses of 47 pUints bearing 212 spikes, secured from 5 different 

 varieties and grown in 3 different localities. He concludes that the composi- 

 tion of 1 row of spikelets is a sufficiently accurate counterpart of the other row 

 of the same spike to serve as a basis for selection. The total and average 

 weight of kernels and the weight of nitrogen vary with the length of straw, 

 but the percentage of nitrogen decreases as length of straw increases. Differ- 

 ences in the comix>sition of different spikes of the same plant are largely or 

 wholly due to difference in nutrition or other environmental conditions and 

 probably not hereditary. Eliminating the abnormally short or tall spikes, those 

 remaining are fairly similar in composition, so that one spike may be selected 

 from them for analysis as a representative of the other heads of the plant. 



II. The distribution of nitrogen in different parts of a wheat spike. — Tables 

 state the results of analyses made for the purpose of determining the distribu- 

 tion of nitrogen among the various parts of the individual spikes. The tabu- 

 lated results as presented indicate that " the composition of the 2 opposite rows 

 of spikelets, on the longitudinal halves of a spike of wheat, is practically 

 identical," especially after rejecting the terminal spikelet which differs from 

 the others. The average weight of kernel and of nitrogen is about the same in 

 ilie upper and lower spikelets of the same head, but the kernels of the middle 

 spikelets have the greatest nitrogen weight per kernel. The nitrogen percent- 

 age increases quite regularly from the tip of the spike downward. The outer 

 I'ows invariably furnished the greatest weight of nitrogen and had the highest 

 nitrogen percentage. 



Results of seed analyses, J. B. S. Norton (Maryland Sta. Bui. 162, pp. 

 235-241, figs. 5).— The author quotes a table of standards of purity and germi- 

 nation of agricultural seeds from a source already noted (E. S. R., 24, p. 440), 

 and states in another table the results of analyses of red, alsike, and crimson 

 clovers, timothy, redtop, alfalfa, and vegetable, flower, and other seeds during 

 1910 and 1911. 



Weeds: Their peculiarities and distribution, W. Brenchley (ScL Prog. 

 Twentieth Cent., 6 (1912), No. 23, pp. 413-431).— A. brief article already noted 

 (E. S. R., 25, p. 536) reported most of the data found in these pages. The 

 author discusses methods of propagation of weeds and the classes of weeds 

 associated with various soil types and crops, and describes briefly a number of 

 parasitic weeds of special interest. 



HORTICULTUEE. 



Miscellaneous greenhouse experiments, C. P. Close and T. H. White (Mary- 

 land Sta. Bui. 1.5S, pp. 97-109). — The results of various experiments conducted 

 during the past few years are reported. 



An experiment was conducted for 3 years with roses, carnations, chrysanthe- 

 mums, and sweet peas to determine the detrimental effect, if any, of sawdust 

 bedding in cow manure. The plants were grown in soils enriched with cow 

 manure and sawdust bedding, cow manure and litter, and cow manure without 

 bedding. From the data as a whole the authors conclude that litter bedding in 

 cow manure is not the best material and that sawdust in cow manure is not 

 harmful, but that everything considered cow manure without any bedding 

 material whatever is preferable. 



Soil and fertilizer experiments with violets conducted for several years in- 

 dicate that the violet plant is very impatient of any excess of soluble salts 

 42049°— No, 8—12 4 



