No. 33.] 13 
normally but eighteen inches tall, and ripens its two-inch ears in 
August, may not apply to the Caragua corn, which grows normally 
fourteen feet tall and ripens its nine-inch ears in October, and 
yet Sachs and other German physiological botanists offer the results 
of their trials with Zea Mays, not mentioning variety, a species 
which varies within extreme limits, and which offers at least 300 
varieties, and probably more, which can be recognized and described. 
The nomenclature of our field cereals is in great confusion. Some 
years ago I collected samples of King Philip Corn, one of the most 
easily recognized varieties, from nine different sources, and received 
under the name King Philip what might have been described as 
seven distinct kinds. We have attempted the nomenclature of maize 
in this report, and the whole value of the attempt, if successful, must 
be ascribed to the detail experiments which precede, and which 
‘furnish the principles which must be used in order to separate and 
define. Just so fast as we obtain diagnostic points in our vegetables, 
eh we hope to succeed in our attempts at close identification. 
ur attempt at classification has been extended to all our varieties 
of vegetables, of which some 1,200 have been grown, but the work 
is a difficult one and requires much careful study. We must await 
the results of another year, and perhaps longer, before we attain even 
approximate completeness. The system outlined in part in last year’s 
report receives additional confirmation as to its value in our this year’s 
work. ‘There is no theoretical reason why our garden and field 
products should not be capable of being identified by description, 
and that agricultural botany should not vie in its power for identi- 
fication with natural botany. If we once recognize that man’s 
wants are reasonably stable, and that there consequently exists in 
the vegetables formed through his selective art a great fixity of form, 
we are encouraged to classificatory work. 
We would call especial\ tention to our observations upon the root- 
ing habits of plants as fouk in the horticulturist’s report. It is only 
as we ascertain the position\ 1 the soil of the plant roots that we have 
a rational interpretation offered to explain the action of fertilizers. 
The fertilizing deeply for shallow-rooting plants, or shallow for deep- 
rooting plants, may explain cases where fertilizer appears to have 
none or but little efficacy, as it is certainly plausible to believe that 
good crops respond to good soil within the area where the roots 
feed. 
Allied to this question of fertilizer is that of nitrogen supply. It 
is now proven beyond reasonable doubt that nitrification is the result 
of the action of an organized ferment, which occurs abundantly in 
soils and in most impure waters. This nitrification is strictly limited 
to the range of temperature within which the vital activity of the 
organisms is confined, proceeding with extreme slowness near the 
freezing point and increasing in activity with a rise in temperature till 
98° F. is reached, and then diminishing and ceasing altogether at 131° 
F. Recent experiments at Rothamstead show that in the absence ot 
phosphates no nitrification will occur. Nitrification seems to occur 

