194 



SCIENCE 



[N. S. Vol. LIV. No. 1392 



gested by Mr. Jerome Alexander in Science, 

 July 22, page 74, to the effect that the evap- 

 orating surface is increased by the comminu- 

 tion of the soil, with the resulting increase of 

 evaporation of the soil water. This in turn 

 results in a greater upward flow of the soil 

 water from below, bringing with it a greater 

 store of plant food than would normally be 

 transported from the depths of the soil. This 

 induced upward movement of the soil water 

 is thought by the author of the note ha. ques- 

 tion to account also for " the curious fact 

 well known to farmers, that in dry weather, 

 cultivation will to a considerable extent fur- 

 nish moisture to the growing crops." 



The value of cultivation (aside from the 

 killing of weeds) is unquestionably the result 

 of a number of diverse factors, the bare enu- 

 meration of which would transcend the limits 

 of the space available in Science. So far, 

 however, as the movements of the soil water 

 are influenced by the comminution of the 

 surface concerned, there are two chief re- 

 sults which prove of benefit to the growing 

 crops. 



By evaporation at the surface, the minerals 

 held in solution are left behind at a locality 

 inaccessible to the feeding roots, which can 

 not long exist at the surface of the land. 

 Cultivation of the surface moves this zone 

 of concentration to the subsurface, and here 

 the roots are able to take advantage of the 

 greater concentrated solution of plant foods. 



The well-known fact that tilth apparently 

 increases the amount of moisture in the land 

 is accounted for by the exact reversal of the 

 hypothesis suggested by Mr. Alexander, the 

 fact being that the comminution of the upper 

 surface of the soil, instead of increasing the 

 evaporation of the soil water, more or less 

 perfectly stops evaporation, and thus conserves 

 the store of soil water. 



L. S. Friebson 



GatlEj Louisiana 



bacteria in the american permian 

 The presence of bacteria in the closing 

 period of the American Paleozoic has been 

 suggested by the condition of the fractured 



reptilian spine, recalling an osteomyelitis, 

 already noted.^ At the time this first notice 

 was written microscopic sections of the fossil 

 spine had not been studied. Since then, I 

 have received four transverse sections through 

 the spine, showing in detail the naturQ of the 

 sinuses which caused the tumefaction. Care- 

 ful search through the sections has failed to 

 reveal any sequestrum, such as is commonly 

 found in modern chronic osteomyelitis, nor 

 were bacteria found in the margins of the 

 calcite filled sinuses. The presence of path- 

 ogenic bacteria in such a situation would be 

 rather rare in a fossil state, since the nature 

 of fossilization would prevent their preserva- 

 tion. It is doubtful too whether we could 

 prove the pathogenicity of such bacteria save 

 by their location. 



Bacteria of the Micrococcus type, so com- 

 mon in the fossil vertebrate material studied 

 by Renault from the Autun of France, are 

 however abundantly preserved in the distorted 

 osseous lacunae. They are similar in all re- 

 spects to those occurring in the fossil bone 

 of fishes pre-\'iously described- from the De- 

 vonian of America and Scotland. The bac- 

 teria, often seen isolated in the terminal bulb 

 of the canaliculus-like burrows, which radiate 

 out from the body of the lacuna, are no doubt 

 those of decay and had nothing to do with the 

 infection producing the osteomyelitis. There 

 seems no doubt that bacteria of this type may 

 be found in any fossil vertebrate material of 

 the type which has been embedded in moist 

 groimd long enough to undergo a slight 

 amount of decay, prior to fossilization. The 

 only reason they have been seen so seldom 

 in fossil vertebrate material is simply because 

 no one has looked for them. They are there 

 beyond any question. 



The bodies which have been interpreted as 

 bacteria, when seen isolated at a magnifica- 

 tion of 1240 diameters, measuring from 1 to 

 2.5 microns, appear as semicrystalline, round- 

 ed, bro^^Tiish bodies resembling minute specks 

 of amber. The question as to whether they 



1 Science, N. S., Vol. LIII., No. 1371, p. 333, 

 Apr. 8, 1921. 



2 Science, N. S., Vol. LI., No. 1305, p. 14, 1920. 



