REPORT OF THE COMMISSIONER OF FISHERIES. yA 
was necessarily affected, as the only source of supply is the fish 
caught for market. As against more than 954,000,000 taken in 1920, 
the past season’s collections reached only 650,000,000. 
The shortage in cod eggs may be ascribed to somewhat similar, 
though not identical, conditions. The body of cod on the shore 
grounds appeared to be smaller than usual, and as the market price 
of haddock offered more lucrative employment for the fishermen 
comparatively few boats engaged in the cod fishery. Egg collec- 
tions of this species in the Gloucester field amounted to 210,040,000, 
while 214,702,000 were secured from brood fish held at the Woods 
Hole hatchery. Haddock eggs to the number of 629,120,000 were 
obtained for the Gloucester station between January 22 and April 29, 
1921, this number exceeding the previous records for that species. 
Weather conditions were generally favorable for flatfish propaga- 
tion, and the egg collections at all stations aggregated 1,980,291,000, 
an increase of 175,000,000 over the previous year. High water-tem- 
eratures occurring toward the latter part of the season in the Woods 
ole region and an unusually early ending of the spawning in Maine 
vaters were factors in curtailing the take of eggs. 
The artificial propagation of the pole flounder (Glyptocephalus 
cynoglossus) was undertaken by the Bureau for the first time dur- 
ing the past year. The presence of this fish in New England waters 
has long been known, but, because of its peculiarly small, soft mouth 
it was not taken by fishermen on the hand lines and trawl lines com- 
monly used. With the coming into general use of the otter trawl in 
the shore fisheries of the section the pole flounder has made its ap- 
pearance in the markets in constantly increasing numbers, and be- 
cause of its food value and excellent flavor it commands a ready mar- 
ket at a high price. With the view of encouraging and assisting a 
new and growing industry an experienced spawn taker was detailed 
to investigate the spawning habits of this species. A close watch 
was kept on the fish landed at the markets during April and May, 
but no fully matured eggs were found until May 22. From that date 
to the end of June 19,410,000 eggs were collected, fertilized, and 
planted on the spawning grounds, and several small lots were taken 
to the Gloucester hatchery for observation. The eggs are semibuoy- 
ant, nonadhesive, and about 0.05 of an inch in diameter, measuring 
approximately 462,000 to the fluid quart. Those placed in a Chester 
jar for incubation did not survive, but the freer circulation of the 
McDonald tidal box appeared to meet their requirements. It is be- 
lieved that the hatching of this fish can be profitably extended during 
the coming season. 
RESCUE OPERATIONS IN MISSISSIPPI VALLEY. 
The salvaging of food fishes in the overflowed waters of the Mis- 
sissippi and Illinois Rivers has continued to be a prominent adjunct 
of the fish-cultural service. In the 1920 season, as early as the water 
stages would permit, this work was begun and continued without in- 
termission as late as weather conditions were favorable. Owing to 
the persistence of high water much beyond the usual time, many 
millions of young fish, which under ordinary circumstances would 
have been left to perish in isolated pools and sloughs, were able to 
