PROPAGATION AND DISTRIBUTION OF FOOD FISHES, 1939 595 
regard to the application of such remedial measures to specimens held 
in outdoor pools. 
The seasonal miniature hatchery, which is a special attraction to 
biology classes, was on display for the purpose of illustrating the meth- 
ods utilized to incubate non-buoyant and semi-buoyant eggs. 
In addition to holding fish in the reserve tanks for distribution to 
applicants in this locality, the aquarium was used in preparing and 
forwarding shipments of live fish and eggs to Puerto Rico and Colombia. 
DISTRIBUTION OPERATIONS 
As the majority of distribution-car trips are made from stations in 
the Mississippi River territory, this service was partly decentralized 
during the year by the assignment of an Assistant Superintendent of 
Distribution to the La Crosse (Wis.) station. This procedure will 
expedite distribution, inasmuch as it is often necessary to move fish 
in that area without delay. This condition was brought about by the 
fact that the ponds constructed in the Mississippi River refuge have 
been very productive, and proper holding facilities for large numbers 
of fish are not available. 
The same number of fish can be carried by truck as by distribution 
car, to destinations within a radius of approximately 300 miles, at 
about one-fourth the cost. For this reason the Bureau is purchasing 
additional automotive equipment, as funds permit, and car No. 7, 
the oldest distribution car in Bureau service, was decommissioned and 
recommended for condemnation. 
Many types of aerating equipment are in use at present by various 
Government and private agencies engaged in the distribution of fish by 
truck. The purpose of this equipment is the maintenance of the oxygen 
content and temperature of the water in the truck tanks at a level 
best suited to the fish during transportation. The Bureau’s distribu- 
tion trucks have been equipped with several different types of aerating 
apparatus in an effort to determine, from experience in actual use, 
which is best suited to this service. Upon conclusion of these trials 
the type of apparatus which has rendered the most satisfactory service 
will be adopted as standard. 
Truck deliveries during the year aggregated 333,950 miles, exclusive 
of the distance traveled by National Park, National Forest, and State 
conservation department trucks engaged in the distribution of fish 
produced at Federal hatcheries. Neither does the above figure include 
travel by individuals and sportsmen’s organizations who called at the 
hatcheries to receive their allotments of fish. The distribution cars 
engaged in the delivery of fish to applicants, and transfers of fish 
between hatcheries, made 77 trips during the year and carried an 
average of 260 pails per trip. The cars traveled 52,899 paid miles 
and 11,789 free miles. Detached messengers traveled 45,152 paid 
miles and 1,639 free miles in delivering fish to applicants. The Bureau 
was again favored with free transportation and reduced rates by a 
number of the railroads. 
