192 
rate, those fed on beef liver produced more melanin 
than those fed on egg yolk. Egg albumen, beef 
suet and brown beans resembled beef liver in this 
respect. These results point directly to the pres- 
ence of substances in the food that exert a specific 
influence upon melanin formation. It is well 
known that tyrosin may be oxidized to melanin in 
the presence of tyrosinase in various organisms. 
In the experiments, any possible tyrosinase in the 
food was inactivated by boiling the latter; and 
tyrosin was present in excess in the tissues. These 
facts suggest the presence of an inhibitor in the 
egg yolk, an idea supported by numerous experi- 
ments in glass. Tyrosin + tyrosinase + egg yolk 
(digested or undigested) produce little or no color, 
while tyrosin + tyrosinase + beef liver (digested 
or undigested) together produce a marked reac- 
tion. That the inhibiting factor may exist in the 
fat content of the food (7. e., lecithin, cholesterin) 
is a possibility now under investigation. 
Woopvrurr, L. L.: Observations on the Origin and 
Sequence of the Protozoan Fauna of Hay Infu- 
sions. 
Data derived from the daily observation, for 
several months, of the sequence of various types of 
protozoa in a large number of infusions of hay. 
Attempt to show that there is a more or less 
regular sequence. Data also on the source of the 
protozoa observed in infusion. 
MacCurpy, H. M.: Observations on the Reactions 
of Asterias forbesti to Light. 
Specimens from six to twelve centimeters in 
diameter respond definitely and are negative in 
their reactions to sunlight. The first visible effect 
of light is a characteristic ventralward movement 
of the affected rays or ray, accompanied by a 
retraction of the tube feet. This reflex takes 
place in specimens either with or without the eye 
spots. The so-called eyes are drawn inward and 
the surrounding spines close more or less closely 
over them in bright light, and the tips of the 
exposed rays are held low. These reflexes may be 
local or general. They tend to inhibit or counter- 
act exploratory movements, retard current im- 
pulses and induce physiological states and relations 
which require readjustment. The direction of the 
new movements is influenced by the retarding ef- 
fect of light and is determined by impulses from 
the central nervous system. The tube feet extend 
readily in shade, and toward the shaded side of a 
ray. light retards extension movements. The 
same is true for the tube feet of Cribella san- 
guinoleuta and Thyone briarius. It thus appears 
SCIENCE 
[N.S. Vou. XXXV. No. 892 
that the tube feet as well as the surface of the 
rays are sensitive to light. The outcome of the 
reaction is a succession of events usually though 
not invariably the result of the checking of some 
movements and the freedom of others. A move- 
ment becoming effective functionally induces co- 
operation in adjacent parts not in that condition. 
A contact stimulus is functionally stronger than 
the light stimulus, but is influenced by the latter. 
GupcGER, E. W.: Oral Gestation in the Gaff-topsail 
Cat-fish, Felichthys felis. 
How the eggs are extruded, fertilized and trans- 
ferred is not known, but when these processes are 
effected the male incubates them in his mouth not 
only until they are hatched by the bursting of the 
shell, but until the yolk has been absorbed and the 
young are able to care for themselves. The largest 
number of eggs taken from the mouth of one male 
was 55. A cement cast of his mouth had a volume 
of 580 cc. The volume of an average-sized egg is 
3.75 ¢.¢., of the 55 eggs 206.3 ¢.c., add 25 per cent. 
for interstices; total space occupied by the 55 
eggs equals 258 ¢.c. This fish was 22 inches long, 
and of average size. The eggs average 19-20 mm. 
in diameter, and the young fish at the end of the 
period of incubation are 85-100 mm. long. The 
length of this period can not be stated definitely, 
since it has been found to be impossible artificially 
to carry the eggs and embryos to the stage of the 
free-swimming young. However, it is about 80 
days. During all this time the nurse does not seem 
to feed. The large eggs would, if spawned on 
sandy or shelly bottoms, be quickly destroyed by 
erabs and by other fish; if laid on a mud bottom 
(where the breeding fish are caught) their consid- 
erable weight would cause them to sink into and be 
smothered by the mud. The habit is common to 
estuarine cat-fish in all tropical and warm tem- 
perate regions. These data are based on five 
summers’ work at the Beaufort laboratory of the 
United States Bureau of Fisheries, in which time 
scores of male fish carrying eggs and larve have 
been captured and autopsied. 
PARKER, G. H.: The Nervous and Non-nervous 
Reactions of Actinians. (No abstract received.) 
Mast, 8. O.: (1) Lhe Behavior of Fireflies and 
tts Bearing on Certain Theories of Tropisms. 
(2) Seventeen Different Definitions of the Term 
Tropism as Applied to Reactions in Organisms. 
(No abstract received.) 
EStEeRLy, C. O.: The ‘‘Oil Fly’’ of California, 
Psilopa petrolet. 
