36 BULLETIN 367, U. S. DEPARTMENT OF AGRICULTURE. 
good as formerly. The quantity of feed produced, however, has 
increased very much, and the change in kind has shown quite con- 
clusively what every stockman already knew, 1. e., that the region 
is better adapted to cattle and horses than it is to sheep. The grazing 
of these small bands of sheep on the range reserve did not affect the 
range in any way detrimentally in the short time they were there. 
It was hardly possible to see where they had been running except 
about the bed grounds, though the herder’s camp was not moved 
while he was on the reserve. 
FUTURE INVESTIGATIONS. 
Summarizing the data so far collected on the Santa Rita Range 
Reserve has not only shown the results obtained, but has pointed out 
several lines along which further data should be collected by con- 
tinuing work in progress, and it has also suggested some new lines of 
investigation. 
Besides keeping watch on the rate of spread of the various grass 
associations mentioned in this bulletin, it is very desirable to devise 
some way of measuring the productivity of the black-grama asso- 
ciation more accurately than has heretofore been possible. Special 
attention should be paid to its rate of spread in the northwest corner 
of the reserve. The question of whether it willsupplant the crowfoot- 
grama association at the lower levels is one of great importance, as 1s 
the time it will take for the black-grama association to cover any 
given area. 
Some accurate measurements as to the rate of spread of the long- 
lived perennial grasses hke Heteropogon contortus and Bouteloua 
eripoda are desirable, as are more data on the productivity of the six- 
weeks-grass areas. The rate of recovery and factors affecting it on 
the plowed areas should be studied carefully. Some seeding experi- 
ments with the local species should be tried in the extreme north- 
eastern corner where these grasses have been very largely killed out. 
Assuming that that part of the recovery pasture lying east of the 
Helvetia road has about reached its normal productivity, it would 
seem to be wise to establish an experiment to determine just what 
the carrying capacity of this area is, by grazing off the forage crop 
with a definite number of animals that are kept on it all the time, 
this number to be based upon estimates already obtained from 
quadrat measurements and hay-cutting records. 
SUMMARY AND CONCLUSIONS. 
The conditions under which the series of experiments of which 
this bulletin is a report of progress were carried on are set forth 
in the introduction. An attempt is here made to summarize the 
results so far obtained, those reported in previous bulletins being 
included for the sake of completeness. 
