THE SEA-HORSE AND ITS YOUNG. 2217 
cess was attained until the autumn of 1866. Nearly a 
year had passed without obtaining a single living speci- 
men, when a waterman brought me two full-grown ones, 
and to my great joy they proved to be “gravid” males. 
Alas ! my oft-repeated experience returned ; for, owing to 
the shock produced by the ordeal of acclimation, they be- 
gan to involuntarily emit their young. None but a work- 
ing naturalist can appreciate the anxiety I then suffered. 
The next day one of my Hippos died, having from de- 
bility first set free all its immature young, which were 
sufficiently developed to indicate plainly their family 
relation. My estimate was that they were twelve-day 
embryos. I now redoubled my efforts to invigorate and 
Save the remaining adult, by solicitously watching every 
circumstance of temperature, eration, and light. In spite 
of all, the emission of the young went on, until instinct, 
prompted by increasing debility, led the parent to expel 
the rest by voluntary effort. How this was done was a 
great point gained. Except a few floating fronds of Ulva, 
other than the fish, there was no object in the water. And 
here the structure of the Sea-horse’s tail should be borne 
in mind, so unlike that of any other fish, covered with 
an envelope, consisting of bony scales; four-sided, and 
Suggesting a small square file; in faculty, prehensile, 
like that of some monkeys; and of considerable length. 
Bending this appendage upwards like an inverted crook, 
thus imparting to it muscular rigidity, the animal pressed 
it against the bottom of the embryonal pouch, which 
Occupied the lower part of the abdomen, thus pushing its 
contents upward, and forcing them out of the opening on 
the top of the sack ; the creature all this time sustaining 
its normal, erect position in the water. The extruded 
young immediately perished. Relieved of his charge, 
