DR. W. H. RANSOM ON THE OVUM OF OSSEOUS FISHES. 
481 
Tincture of opium. — On adding two or three drops of tincture of opium to a cell con- 
taining ova, vividly contracting, the movements seemed to cease for a time, but the 
sulcus remained. In about three minutes the movements reappeared and continued for 
half an hour, after which more tincture of opium was added, and still the contractions 
were found going on with moderate vigour an hour later. 
Spirit of wine. — A few drops of spirit of wine added to a cell containing freely con- 
tracting ova, either did not affect the contractions and oscillations at all, or slightly- 
quickened them. 
Tincture of cantharides acts much the same as spirit of wine does ; after twelve hours 
eggs treated with it were developing normally. 
Solution of potash. — A very minute drop of Liquor Potassse, L. P., was mixed with 
the water of a cell containing several freely contracting ova. The inner sac a t once 
burst, its contents escaped into the cavity of the egg, and it was soon crumpled into a 
distinctly membranous bag, still marked by the ripples due to the previous contractions. 
No further cop tractile waves appeared, nor did it dissolve. After a very few minutes 
the yelk-sac burst, the solution having been too strong. 
Strychnia. — A neutral solution of acetate of strychnia, 2 grs. to 480 grs. of water, was 
added, in small amount, to a cell containing vigorously contracting ova. No visible change 
appeared in the movements, and after twelve hours the eggs were normally developing. 
More strychnia was then added, but no result followed. 
Aconite. — A solution of 5 grs. of extract of aconite in 60 minims of spirit of wine 
was added, by drops, to a cell containing freely moving ova, but no effect was observed, 
except perhaps a slight acceleration of the movements. 
Hydrocyanic acid. — A few drops of dilute hydrocyanic acid (2 per cent.) added to the 
water in which ova were actively contracting, produced no effect in a quarter of an 
hour, during which time I watched. 
In each of these experiments there were some unimpregnated eggs present, easily 
recognized by their irregular, often detached, proligerous disks. In no case was there 
any difference observable between them and the fertilized ones as to the action of the 
poisonous agents. 
Hydrochlorate of morphia. — Two drops of a strong spirituous solution of hydrochlo- 
rate of morphia were added to some unimpregnated ova, which had been deposited nine 
hours, and were rapidly contracting and oscillating. No effect following, four drops 
more were added without result ; again four drops were added, and during a quarter 
of an hour no result was observed ; twelve hours later they were all opaque. 
Chromic acid. — Eight days after impregnation, a healthy developing embryo was let 
out of the yelk-sac into a weak solution of chloride of sodium and chromic acid, and 
the contractions at the lateral poles, mentioned by Reichert, were seen to go on appa- 
rently unchecked. 
Ammonia. — Contractions of the yelk continue in eggs placed in a very weak ammo- 
niacal solution of carmine ; and even when the egg is ruptured, and the inner sac 
