DR. W. H. RANSOM ON THE OVUM OE OSSEOUS EISHES. 
487 
Control experiment 3'. — The last experiment was repeated with eggs which had been 
impregnated in the usual way. Ordinary distilled water was used, care being taken to 
wash away all adhering seminal fluid. Twelve hours after, they were contracting freely, 
the germinal disk was cleft into a coarse mulberry mass. Twenty-six hours after, the 
contractions were rapid, the germinal disk a fine mulberry mass : a few eggs were 
opaque. Thirty-five hours after, they were contracting freely, and the germinal mass 
covered nearly half the yelk. Forty-eight hours after, they were contracting as before, 
and the germinal mass covered nearly three-fourths of the yelk. The water, which had 
not been changed, was faintly milky, neutral in its reaction, did not precipitate baryta- 
water : on concentration it remained neutral, and contained faint traces of a phosphate. 
In this instance also the presence of several opaque eggs with ruptured inner sacs makes 
the examination of the water for products of respiration unsatisfactory. 
Control experiment 4. — I fertilized in the usual way a number of eggs in a large dish 
in tap-water, which was changed daily ; and as there were some eggs in which the 
impregnation had failed to take place, they could be compared with the control experi- 
ment 3, to ascertain whether distilled water modified the contractions and development 
of the germ. During the first forty-eight hours no difference was observed when they 
were compared with control experiments 3 and S'. 
Experiment e . — I placed thirty-five unimpregnated eggs, fresh from the pike, in one 
of the above-described cells, taking care that all were well bathed with distilled water, 
and I sealed the cover quickly with hot wax. Four hours after, they were contracting 
freely, but with a smooth discus proligerus. Twelve hours after, contracting as before, 
they showed less lobulation of the discus proligerus and rarer separation of it than did the 
eggs in control experiment 3. Twenty-six hours after, they were moving freely, but 
less so than those in control experiment 3. Unfortunately, however, the luting had 
got loose, and an air-bubble had entered. Thirty hours after, the contractions had 
ceased ; and the yelk-ball was round, except in those eggs near the air-bubble, which 
were still contracting well. Fifty-three hours after, all were motionless. 
Experiment f was the same as the above, with only eighteen eggs in the cell. A 
small air-bubble got in, but the yelks ceased to contract in thirty-five hours. Those 
nearest to the air-bubble continued to move the longest, and became still ultimately by 
rupture of the inner sac, which explains their early cessation. 
Experiment g was the same as the above, with but nine eggs in the cell. At twenty- 
six hours after, greater vivacity of the yelk-contractions and more lobulation, and sepa- 
ration of the discus proligerus were observed than in the eggs of experiment e. at the 
same time. After thirty-five hours they were still contracting. After fifty-three hours 
they had ceased to move. Into this cell also a very minute air-bubble found its 
way. 
Experiment h was the. same as the above, but with thirty eggs in the cell, tallow 
being used instead of wax to seal the cover. Twelve hours after, they rotated less freely 
than the control ova to which they belonged. Twenty-three hours after, they had all 
MDCCCLXVIL 3 U 
