344 



SCIENCE. 



[N. S. Vol. XXII. No. 559. 



ments have often suggested that rust, at times, 

 either attacks wheat from the soil in some 

 form or manner, not now known, as character- 

 istic of the life history of rust, or that it may 

 come in some manner from the seed. This 

 will at once suggest to those who are familiar 

 with the investigations upon the rusts of 

 cereals, the studies conducted by Professor 

 Ericksson, of Stockholm, and his odd and un- 

 demonstratable mycoplasm theory. That au- 

 thor by his experiments seems to have demon- 

 strated that in some manner a rust of wheat 

 (Puccinia glumarum) of that region can be 

 transmitted by the seeds, and claims to have 

 demonstrated by structure studies certain 

 micro-protoplasmic bodies directly associated 

 with the cellular structure of the young wheat 

 plant in such a manner that they are able to 

 transmit the rust infection by finally trans- 

 forming into filamentous structures in the 

 aftergrowth from the embryo. 



Through persistent studies upon this phase 

 of the rust question we are now able to point 

 out a more rational possible explanation of 

 the transmission of rust through the seed of 

 wheat, if it really ever is transmitted in that 

 manner. Professor Ericksson in his exjjeri- 

 ments enclosed wheat from the time it was 

 seeded until the time of maturity in certain 

 germ proof glass cages and found that rust 

 still appeared in the crop.^ Bolley at the 

 North Dakota Experiment Station several 

 times duplicated this work.^ He used sound 

 wheat grains externally treated and in no case 

 was able to secure rust under the conditions of 

 culture; that is, was unable to confirm the 

 results of Ericksson. It is possible that the 

 wrong kind of wheat was selected in order to 

 prove this work. In the experiments just 

 cited, Bolley used the best selected grains of a 

 particular kind of wheat which was known to 

 rust easily. It was not certain, however, that 

 the grains used had grown on rust-attacked 

 mother plants. Late observations at the 



^ Dr. Jacob Ericksson, ' A General Review of the 

 Principal Results of Swedish Research into Grain 

 Rust,' Botanical Gazette, Vol. XXV., No. 1, 1898. 



- Bolley, in Centralblatt filr Bacteriologie, 

 Parasitenkunde und Infectionskranklieiten, Zweite 

 Abteilung, IV. Band, 1898, Nos. 23, 24 and 25. 



North Dakota Experiment Station Botanical 

 Laboratory, in which numerous samples of 

 wheat harvested from the badly rusted crop 

 of 1904 were examined, now allow us to make 

 the definite statement that wheat grains from 

 badly rusted naother plants quite often, indeed, 

 in some strains are quite uniformly internally 

 infected by wheat rust filaments to such ex- 

 tent that spore beds are formed bearing both 

 uredo-spores and teleuto-spores {summer 

 spores and winter spores) beneath the bran 

 layer. In some samples of the rust-infected 

 crop of 1904, as high as thirty per cent, of all 

 grains harvested were so infected with the 

 stem rust (Puccinia graminis) and spore beds 

 bearing both types of spores were found vari- 

 ously located beneath the bran layer of the 

 grains and about the embryo wheat plants. 

 The spots or spore beds are most commonly 

 located immediately at the germ end, causing 

 a black or blighted appearance, but are often 

 found on other portions of the berry, especially 

 along margins of the grooves. It is also 

 found that these grains, thus affected, germin- 

 ate as freely as any other wheat grains. 



These new observations have opened up a 

 new line of investigation, but it is too early to 

 aifirm that wheat rust attacks may come in 

 this direct manner from the seed. If, how- 

 ever, later experiments should confirm this pos- 

 sible mode of rust propagation, these obser- 

 vations must iindoubtedly throw a new light 

 upon the Ericksson mycoplasm controversy 

 and place another strong emphasis on the im- 

 portance of proper seed selection and grading 

 of grain in farm practise. The fact that rust 

 thus attacks the wheat grain by way of its 

 attachment is also an apparent explanation 

 of why rusted wheat often fails to properly 

 mature the seed even though there is yet plenty 

 of strength in the parent plants. 



Henry L. Bolley, 

 F. J. Pritchard. 



North Dakota x\gricultural College, 

 July 11, 1905. 



APPARATUS TABLES FOR ELECTRICAL LABORATORIES. 



The apparatus tables, here described, were 

 designed to meet the needs of an advanced 

 laboratory in electrical measurements. The 



