464 
separated, (3) the loose union of one or more eggs 
or parts thereof, (4) the greater or less fusion of 
one and one half to sixteen or more eggs into one 
large complex. 
Observations upon living and preserved materials 
clearly showed the nature of the subsequent his- 
tory depended upon the nature of the union of the 
component eggs. When eggs or parts of eggs 
were either partially separated or brought in loose 
contact, the development of the component eggs 
was independent, showing no influence of the one 
upon the others. Two or more normal plutei re- 
sulted, either separate or welded together into 
twins. A very considerable number showed vary- 
ing stages in the fusion and regulation whereby 
several blastule or gastrule were reorganized into 
one giant or irregular single blastula, gastrula or 
pluteus. These changes involved interesting regu- 
latory processes in the skeleton, gut, size, shape, 
etc., of the individual eggs. They also showed an 
independent rate of development with a frequent 
dominance of one and the gradual reduction and 
disorganization of the other eggs in such a par- 
tially fused mass of eggs. 
Common Atypical Embryos and the Diverse 
Methods by which they are Produced: A. J. 
GOLDFARB, College of the City of New York. 
The Influence of Magnesium Chloride on the Fer- 
tilizing Potential of Spermatozoa: R. A. Bup- 
INGTON, Oberlin College. 
The sperm of Arbacia punctulata was used. 
This was treated for various lengths of time (5 to 
80 minutes) with different solutions of MgCl in 
sea water; .1, .2, .3, .4, .5 and .6 gm. solutions 
were employed. Such sperm was then used in 
artificially fertilizing eggs of the same species, two 
questions being kept in mind, viz., (a) Will such 
sperm cause earlier cleavage of eggs than will 
normal sperm? (b) Will such sperm fertilize a 
larger percentage of eggs than will normal sperm? 
A positive result was obtained for the first prob- 
lem when sperm were exposed to weak solutions 
for 5 to 15 minutes. As to the second problem, 
no marked increase in relative number of eggs fer- 
tilized, over the proportions shown by the control, 
could be detected. 
The complete paper will probably be published 
in The Biological Bulletin. 
SCIENCE 
[N.S. Von. XXXV. No. 899 
The Lifect of Narcotics upon the Development of 
the Hen’s Egg: A. M. REESE, West Virginia 
University. 
To be published in Science. 
Effect of Commensal Plant Cells in Altering the 
Rate of Starvation in Scyphomeduse: ALFRED 
G. Mayer, Carnegie Institution of Washington. 
The scyphomedusa Cassiopea ~ xamachana, of 
Tortugas, Florida, is infested with Zooxanthelle, 
which when exposed to daylight operate through 
photo-synthesis to fix the carbon given off as a 
result of the medusa’s metabolism, and at the 
same time to set oxygen free, thus serving as an 
efficient aid to the vital processes of the medusa. 
If the meduse be maintained in darkness, the 
zooxanthellz are rendered inactive, and the medusa 
starves more rapidly than if exposed to the diffuse 
light of the laboratory. In darkness the course of 
starvation is represented by the formula 
y=W(1—a)s, 
where y is the weight upon any day a after 
starving has begun, and W is the original weight 
when starving began. a is the index of starvation, 
for it imcreases as the rate of starvation in- 
creases. When the meduse are starved in dark- 
ness, a@ ranges from .075 to .205, but in diffuse 
daylight it is less, varying from .046 to .15. When 
the meduse are starved in diffuse daylight they 
lose weight more slowly than if in the dark, and 
the formula for starving in the light may be rep- 
resented by 
w+ w(l + B— 4) 
yS=W(1i—a)t*+A (rr 
x [(L—a)21+ (1—a)2-2(1+4+ 6—8) 
+ (1—a)2-3(1+ p—8)? 
+ ete. .-- (1—a)2-7(1 + B—6)#-4] 
ig wl + Bi) 2; 
where w is the original weight of plant cells in 
the medusa, 8 their coefficient of increase, @ their 
coefficient of mortality, and A the coefficient of 
assimilation of these cells by the medusa. The 
meduse may be starved 41 days, and still remain 
alive when their weight has been reduced to one 
hundredth of its original mass. If starved in sea- 
water which has been sterilized by heating to 
72° C., and then cooled to normal temperatures, 
the medusz lose weight about 13 times more rap- 
Movements Cease 
at 
Temperature of Movements Cease 
Greatest Activity at DEG Oeawwes Bi 
Aurellia from Tortugas ..............0006 
Aurellia from Halifax, Nova Scotia........ 
—1°.4 
---|7°.75 to 11°.8C.| About 28° C. 
36°.4 to 38°.4 
18° to 23° 29° to 29°.7 
38°.5 
29° to 30° 
