578 | The American Naturalist. [June, 
action of the environment. He resumed his studies a short time © 
since, and gives us the following results. 
He has experimented on young flounders (Pleuronectes flesus), in 
which the eye had not yet entirely left the ventral face. Already the 
pigment of this face had largely disappeared ; the animal swam with 
the left side down, and on the dorsal side the color was pronounced. 
Blackening the cover and sides of a glass jar, he put it with the young 
fish within on a support, and arranged beneath the vase a mirror in © 
- such away as to reflect the sunlight into the vase. Now the dorsal 
side of the fish would be in darkness, and the ventral side exposed to - 
the light, thus reversing the normal conditions. The water was renewed 
frequently, and the fish given all the food they required. Other 
flounders were put into a similar vase, which was normally lighted. 
The results were as follows : 
Of thirteen fish lighted from below three only kept the usual colora- 
tion ; the others showed a greater or less quantity of pigment cells and 
chromatophores. Under these conditions it seems probable that the 
absence of color from animals in normal conditions is due to the 
difference of circumstances, and that light is the agent which deter- 
mines the development of pigment cells. It can, nevertheless, not be 
the only one; there exists coloration among animals living in the 
obscurity of profound depths.—Reewe Scientifique. 
Parmella etheridgei.—Mr. C. Hedley records a new mollusc, 
Parmella etheridgei Brazier. It was found on the stems and leaves of 
the palms growing on the lower ground of Lord Howe Island, It oh 
the second species of a long-lost genus. (Records Australian Museum, — 
Vol. I., No. 4.) 
The Spawning Seasons of San Diego Fishes.—The follow- 
ing is a summary of observations on the spawning seasons of the San : 
Diego fishes. Those marked with an asterisk (*) are viviparous, and os 
etime . 
the length of gestation has not in all cases been made out. 
indicated for the viviparous species is that during which young, some 
times well developed, were taken : 
Heterodontus francisci, from January to April; *Sgualus —_ - ; 
from July 20th to September ; *Scylliorhinus ventriosus, egg fo 
ready to hatch Dec. 27th; *Galeus californicus, September qth t 
| F ebruary 14th ; * Zriacis semifasciatus, September 6th to October 7th; i 
*Rhinotriacis henlei, September 7th; *Galeorhinus syopterus, Ange 
goth ; Clupea mirabilis, December 11th to February ; Stolephoris ee 
ringens, April, May, and June ; S. delicatissimus, April, May, and J s n 
) 
