232 



SCIENCE 



[N. S. Vol. XXXIII. No. 841 



ilization succeeded in. making it produce 

 wlieat, their theory would seem to be without 

 ground. My experiments in sterilization re- 

 sult in either good or bad wheat according to 

 what I do to the seed planted therein, though 

 there can not be any question but what in 

 some soils increased amounts of ammonia 

 through sterilization do have something to do 

 with the results. 



Experiment by Professor T. L. Lyon, of 

 Cornell University, Bulletin 2Y5, " Upon the 

 Effect of Steam Sterilization on the Water- 

 soluble Matter in Soils," attempts an explana- 

 tion of the peculiarities of growth of the 

 wheat plants upon soils after steam steriliza- 

 tion through differences in the soluble content 

 of the soil resulting in differences in density 

 of the soil solutions, etc. He also, however, 

 seems to have great difficulty in accounting 

 for some of the peculiar actions of the grow- 

 ing wheat plant upon such treated soils and 

 solutions, especially in explaining what ap- 

 pears to be a really injurious effect upon the 

 first growth from the seedlings, though finally 

 followed by actual increase in crop. 



In our experiments, we are able to explain 

 most of these peculiarities of growth, noticed 

 both in our cultures and those of Professor 

 Lyon's admirably conducted trials, upon a 

 biological relation of the wheat plant to cer- 

 tain actual disease-producing organisms and 

 their growth relations to the crop plant, and 

 to the various interreacting soil relations, 

 which react both upon the crop plant and 

 upon the disease producers. 



In our experiments we find that both soil 

 and seed may be, and usually are, infected 

 by several very destructive wheat-destroying, 

 parasitic fungi. Indeed, these are found to 

 be apparently cosmopolitan in distribution 

 with the wheat plant. They are especially 

 transmitted in the seed internally, and, it 

 seems quite certain, are sufficient in their in- 

 fluences to account for most of the causes of 

 rapid first-crop deterioration, and for the 

 difficulty which farmers have in introducing 

 any sort of culture, which will again raise the 

 standard of crop. Their exclusion, in so far 

 as it is perfectly or imperfectly done, is suffi- 



cient to account for the anomalies indicated 

 in soil sterilization experiments. However, in 

 our experiments our results and conclusions 

 have always been vitiated whenever these 

 fungi were not eliminated. 



I do not question that soil sterilization does 

 change the bacterial content or that it does 

 influence the soluble content of soils, but I am 

 inclined to think that disease-infected seed 

 and disease-infected soil will eventually be 

 found to have much more to do with the 

 irregularly corresponding conclusions, which 

 have been drawu by various experimenters 

 upon crop rotations, upon soil-fertilization 

 experiments and upon soil-disinfection ex- 

 periments than they have ever suspected. 

 Indeed, I have but slight doubt that the whole 

 theory of auto-intoxication (toxine theory) as 

 applied to cropping plants, is virtually viti- 

 ated in its conclusions, because of a lack in 

 eliminating the influences of pathogenic or- 

 ganisms in the experiments. 



h. l. bolley 



Agbictjltueai College, 

 NoETH Dakota, 

 November 1, 1910 



V 

 TERTIARY DEPOSITS OF NORTHEASTERN MEXICO 



During the past two years, the geologic 

 work under my direction in southwest Texas 

 and northeast Mexico has resulted in the ac- 

 cumulation of a mass of information which 

 materially adds to our knowledge of the Gulf 

 Tertiaries. The fieldwork was carried on by 

 Messrs. W. E. Cummins and W. Kennedy, as- 

 sisted by Mr. J. M. Sands. 



The first year's work by Professor Cum- 

 mins was a general examination of the north- 

 eastern Mexico for artesian water. Following 

 this, I had a careful section made of the 

 Cretaceous and Tertiary deposits along the 

 Eio Grande, and then traced the contaei be- 

 tween the two systems southward into Mex'co 

 as far as this could be done within the scoi, ^ 

 permitted by our economic work. The wide 

 spread occurrence of the different phases of 

 the Eeynosa formation prevented direct con- 

 nections of the exposures of the underlying 

 deposits in some places, but we were able to 



