PROGRESS IN BIOLOGICAL INQUIRIES, 1938 53 
water) good sperm is still effective after 24 hours. In greater dilu- 
tion the sperm perishes sooner. These experiments indicate that 
simultaneous spawning of the majority of adult specimens and 
crowding of spawners on spawning beds are essential for the suc- 
cessful propagation of the oyster. 
Respiration—The study of oyster respiration was undertaken 
with the view of determining the effect of environmental conditions 
on this fundamental living process. An understanding of the factors 
controlling the uptake of oxygen by an aquatic mollusk is especially 
necessary for the study of its carbohydrate metabolism and of other 
metabolic processes which result in the accumulation of glycogen, 
heavy metals, calcium, and other elements which, from the nutritive 
point of view, are important food constituents of the oyster meat. 
Using the metabolism chamber specially designed for this work 
and employing the technique perfected during the previous summer, 
Dr. Galtsoff and G. I. Mishtowt carried out a number of experiments 
studying the effect of lowered salinity and increased CO, tension on 
oxygen consumption. It has been found that in all the experiments 
with diluted sea water the oyster used an average of 13.6 percent 
more oxygen in a salinity of 24 parts per thousand than in a salinity 
of 32. 
Experiments with CO, consisted in bubbling this gas through sea 
water and determining the rate of oxygen consumption. It was found 
that CO, has a depressive effect on oxygen consumption, which begins 
to decrease with the decrease of hydrogen ion concentration. The 
maximum effect is obtained at pH 6.0 or lower, the oyster under these 
conditions using practically no oxygen and presenting all the appear- 
ances of being narcotized. 
Further plans for this investigation comprise the determination 
of respiratory quotients of oysters at different times of the year and 
under various environmental conditions, and a study of the effect. 
of various pollutants on respiration. 
OYSTER CULTURAL STUDIES 
Propagation of oysters in Long Island Sound.—The oyster industry 
of Long Island Sound and adjacent waters depends upon an abundant 
supply of seed oysters for its perpetuation. Since the rate of survival 
of Connecticut seed oysters transplanted to other waters is high, 
and their growth in a new environment is rapid, there is always an 
extensive demand for them, and seed producing has become a prof- 
itable industry of the State. However, owing to the frequent failure 
of oysters to set, the industry has not been in a position to supply the 
much needed seed oysters. In addition to the poor natural setting, 
the destruction of spat and seed oysters by various pests, especially 
starfish, is tremendous. The protection of young oysters from their 
enemies constitutes, therefore, another vital problem for the ovster- 
men. Both problems have been under investigation by Dr. V. L. 
Loosanoff and James B. Engle at the Fisheries Laboratory at 
Milford, Conn. 
Spawning and setting—Continuing the investigations begun in 
1937, spawning and setting of oysters were observed at a chain of 
15 stations extending from Bridgeport to Morgan Point and east to 
New Haven, thus covering the most important part of the Connecti- 
