584 
CHARLES WILSON GREENE 
A DISCUSSION OF THE INJURY INFLICTED IN THE MARKING 
PROCESS 
Xo physical injury is imposed upon the fishes up to the point 
where the 7 mm. hole is punched in the tail for the insertion of 
the marking button. This injury is relatively insignificant. 
True it produces a transient stimulus to the skin which leads to 
physiological reflexes for the moment. If the button is carelessly 
inserted so as to continually compress the tissue of the caudal 
fin, this may lead to further stimulation of a certain degree. 
A factor of far more importance than the direct physical injury 
is the possible asphyxiation that results during the handling of the 
fish in air. When a fish is taken out of the water, the water 
quickly drains from the mouth cavity and from over the gills, 
thus exposing the latter to air. When the air comes in free con- 
tact with the gill filaments, even better aeration may occur than 
when the fish is in water. The trouble comes when the gill fila- 
ments no longer supported by water adhere together in a mass. 
Under these conditions asphyxiation takes place rapidly. The 
anatomical arrangements of the gillcovers and gills in different 
species are, for the above reasons, largely responsible for variations 
in the rapidity with which asphyxiation occurs. In the salmon 
one cannot but note the endurance of the fish against asphyxiation 
and the ease with which this condition may be removed by arti- 
ficial respiration. A fish can endure a considerable degree of 
asphyxiation without any notable evil effects unless that degree 
be carried to the point which results in loss of function to the respir- 
atory center. 
A DISCUSSION OF THE INFLUENCE OF HANDLING ON THE 
MIGRATION OF THE SALMON 
A most important question that arises in this experiment is 
this: What effect will the handhng have on the future course 
of migration, and the manifestation of the migratory instincts 
in the salmon? It will have little effect for the following 
reasons : 
