NOTES AND ABSTRACTS. 



153 



illustrated. The author considers the " varying rates of growth, time of 

 microspore division, ability to increase the cytoplasm, and inability in many 

 cases to develop normally, seem to be the outward expression of the differential 

 ability of these new chromosome combinations to carry on cell metabolism." 



F. J. C. 



Symbiosis, Possible, between Legume Bacteria and Non-leguminous Plants? 



By Thos. J. Burrill and Roy Hansen (U.S.A. Exp. Stn., Illinois, Bull. 202, 

 pp. 111-181 ; 17 plates). — The authors state that the nodule bacteria studied 

 were found to be true Schizomycetes, actively motile by means of a single polar 

 flagellum, but the nodules of the non-Leguminosae Ceanothus, Cycas, Alnus, 

 and Myrica, which are said to be concerned with fixation of atmospheric nitrogen, 

 are not caused by Pseudomonas radicicola. The nodules of Ceanothus are 

 wholly different morphologically from those of the Leguminosae. The evidence 

 as to the dissimilarity of the nodules of Elaeagnus and Podocarpus caused 

 by these organisms is not conclusive, nor is the proof of the fixation of nitrogen 

 conclusive. The preliminary experiments of attempting the infection of non- 

 Leguminosae with nodule bacteria failed. 



The adaptations of the nodule bacteria are constant. Such factors as acidity 

 or alkalinity of the medium, the use or absence of organic or inorganic substances 

 in the medium, or the presence or absence of combined nitrogen in the medium, 

 do not affect the virulence nor break the special adaptations. 



A full bibliography is appended. — A . B. 



Tobacco Beetle, The : An Important Pest in Tobacco Products. By G. A. 



Runner (U.S.A. Dep. Agr., Bull. 737, March 1919 ; 16 figs., 9 tables, 14 plates). — 

 This beetle (Lacioderma serricorne Fab.) feeds and lives mainly in dried vegetable 

 products, and is a most destructive pest of manufactured tobacco and tobacco 

 products. It must not be confused with a field insect, Epitrix parvula, which 

 attacks growing tobacco. 



The injury caused by the tobacco beetle is very great, owing to its habit of 

 occupying its food substance during all stages of its life. The principal damage 

 is done during the larval stage. The presence of refuse, excrement, dust, and 

 dead beetles renders the manufactured product unsaleable. 



Cigars and pressed tobacco are injured by the insect burrowing small cylindrical 

 tunnels, which later become filled with dust and excrement. A large portion 

 of the interior of cigars may be destroyed without external evidence of injury 

 to the wrapper. Injured cigars do not draw well, burn unevenly, and dust is 

 drawn into the smoker's mouth. Among destructive agencies employed in the 

 control of the insect are : 



1. High temperature or steam (a temperature of from 125 0 to 140 0 F. 

 continued for several hours, or i50°F. for a short time) kills all stages of the 

 beetle. 



2. Treatment by cold storage. 



3. Trapping or destruction by mechanical means. 



4. Fumigation with carbon-bisulphide, hydrocyanic gas, or other fumigants. 



5. Sterilization of infected tobacco by means of exposure to Rontgen or 

 X-rays.— V. G. J. 



Tomato as a Farm Crop for the Canning Factory, The. By C. G. Woodbury 

 and H. J. Reid (U.S.A. Exp. Stn., Purdue, Circ. 59, March 1917; 13 figs.). — 

 Tomatos respond to thorough cultivation and growers should give them all 

 possible attention. The yield may be easily reduced several tons per acre by 

 neglecting the crop at critical times. No larger acreage should be set than can 

 be well cultivated. This circular deals very thoroughly with all points of 

 culture on a large scale, and gives formulae for the control of insect and disease 

 troubles.— 7. G. /. 



Vegetable Evaporation (Bull. State Comm. Hort., California, viii. 3, March 1919 j 

 24 figs.). — Contains many interesting papers, including one on "The Evaporation 

 of Vegetables." Experiments by biological chemists show that all green vege- 

 tables contain a substance they call vitamen, which is necessary to the growth 

 of young animals- and children. It is thought that drying the vegetables does 

 not destroy this compound. The weight of evaporated vegetables is ^ to 

 that of canned vegetables, and the process is much cheaper. They are easily 

 prepared, and keep well if stored in tins or air-tight cases. — V. G. J. 



Weeds, Whitlow Peppermint, and Black Mustard, Control of. By R. Robson, 

 M.Sc. (Jour. Bd. Agr. vol. xxvi. No. 1, April 1919). — A descriptive and 

 illustrated article on the two above-mentioned weeds, Whitlow Peppermint 



