THE SEA-HORSE AND ITS YOUNG. 231 
pass off by atrophy, but is really a wise provision for the ` 
creature’s support by absorption, during the few days 
which constitute the most critical period of its life. 
This fact I have demonstrated elsewhere by obser- 
vations from the spawn to maturity. But in these and 
similar cases, the animal is simply nourished by some 
superabundance in itself. Ruling out lactation, and the 
placental phenomena of gestation, is there any instance in 
which, as a normal fact, the young feeds upon the parent? 
This fact, seemingly so anomalous, I assert for the Hip- 
pocampus, although its physiology I may not be able to 
explain. The male Sea-horse not only hatches the eggs 
in the embryonal pouch, but also feeds the young by al- 
lowing them to absorb a portion of himself. This is done 
_ during the embryo’s consumption of the placental yolk, 
and also, especially and more rapidly, after that source of 
food is all exhausted. Of course, upon receiving the ova 
the pouch might be supposed to be considerably distend- 
ed. This distension is really very trifling. And during 
development the enlarging of the sack might be expected ; 
but it is inappreciable. At the time of receiving the 
spawn, the wall of the pouch is not less than three lines 
thick, and well stored internally with fat. At the time of 
expulsion of the developed fry, the same sack is not half 
_ a line thick, and hangs flaccid on the animal, a mere thin 
membrane. In due time it becomes again thick, firm, 
and fat as before, and in such state has been mistaken by 
me for a gravid condition. This interesting fact of a true 
marsupial nourishment, and of so unique a character, 
although suspected, was not accepted, until established 
by dissection, and observation of a male that had gone 
through the course described. Moreover, I believe in 
part may be thus explained the impulse to that forcible 
