432 



SCIENCE. 



[N. S. Vol. XX. No. 509. 



to mean that in all cases the recognized 

 form and functional differences are tem- 

 porary modifications and that all are one 

 natural species. There is really a very 

 important matter here which we trust we 

 shall soon know more about. If those 

 which normally inhabit one species of 

 leguminous plants can be modified by arti- 

 ficial cultures so as to grow upon another 

 species of legumes, may further modifica- 

 tions be induced so that growth may take 

 place upon some plant not a legume? 

 There is no known reason why legumes 

 particularly are hosts of these organisms 

 to the exclusion of other kinds of vegeta- 

 tion. As a matter of fact, there are other 

 and very different kinds of plants upon 

 which similar root tubercles are found, 

 namely, shrubs or trees of the genus Alniis 

 or alder (not elder) ; two or three species 

 of the family Eleagnacese, European shrubs 

 sometimes cultivated with us for their 

 silvery foliage; and — what appears more 

 strange— upon coniferous trees of the 

 southern hemisphere belonging to the genus 

 Podocarpus. It has now become well 

 known that the root tubercle organisms 

 peculiar to alfalfa are not very widely dis- 

 tributed in our country and that in many 

 cases the former can not be profitably 

 raised without artificial inoculation of the 

 soil. In such cases a remedy is found in 

 scattering earth taken from a field where 

 the plant has been successfully grown and 

 where the nodules on the roots have been 

 observed. A similar statement may be 

 made with reference to soy beans, and there 

 are areas, though not so common, where the 

 bacteria which form tubercles on the roots 

 of clover do not exist. In such areas the 

 clover plant no more contributes to soil 

 fertility than do other kinds of green vege- 

 tation. 



We have asked: Can these legume or- 

 ganisms or some of them be made to form 



tubercles on other plants, for instance, 

 upon maize? Here is a matter of the 

 greatest moment. Undoubtedly they have 

 some time in the past become adapted to 

 leguminous vegetation. There is nothing 

 to prevent the supposition that they may 

 possibly be made to adjust themselves to 

 corn. If so, what a triumph this would be 

 for scientific experimentation. What an 

 advance it would mark for scientific agri- 

 culture. We know that corn can be very 

 decidedly modified in its chemical composi- 

 tion by processes of breeding. Types of 

 grain can be produced in which, for in- 

 stance, the nitrogenous percentage is great- 

 ly increased, and so a long way improved 

 as food for man and beast. If, in addition 

 to this, Indian corn can be made to furnish 

 itself, through accommodating bacteria, 

 with this higher nitrogen content directly 

 from the exhaustless storehouse of the air, 

 the agricultural miracle of the age will 

 have been wrought. No one can predict 

 whether or not this will ever come to pass. 

 But from what is now known the endeavor 

 to bring it to pass seems at least worth 

 while. 



Some years ago there were put up in cer- 

 tain German laboratories substances under 

 the name of nitragin which were supposed 

 to be pure cultures of living bacteria sev- 

 erally suitable for different leguminous 

 crops, and it was thought that great results 

 would follow the proper application of 

 these cultures to fields seeded with the vari- 

 ous legumes. Patents were taken out in 

 Europe and in this country protecting the 

 manufacture and use of these substances, 

 but little seems to have come of the matter. 

 Now the Department of Agriculture at 

 Washington is sending out what are sup- 

 posed to be improved cultures for a similar 

 purpose, and some very favorable reports 

 of their use have been made. It is too soon 

 to determine how valuable the results are 



