the Development of Anableps Gronovii. 433 
one forms a nest upon the-bottom with pieces of grass and 
other vegetable substances, which are woven together, form- 
ing a covered structure, with two openings, so that when the 
fish enters it can pass through without being required to turn 
round to come out. If the materials prove too light, and show 
a tendency to float, they are loaded with stones till the nest 
is securely anchored.* 
_ The other species constructs its abode upon some aquatic 
plant elevated above the bottom, or upon some submerged 
branch or twig of a tree. During incubation, the ova are 
guarded by the male, and protected against the depredations 
of the females, which are always ready to devour the eggs 
almost as soon as deposited.+ 
In another group of fishes, the eggs are neither scattered 
upon the bottom nor deposited in nests, but assume a more 
intimate relation with the parent, though still conforming to 
the oviparous mode. In the Pipe fishes they are attached to 
€ body of one of the parents. In one species, Syngnathus 
ophiodon, the eggs merely adhere to the under side of the 
abdomen of the male, where they remain till hatched. But 
in S. acus, as observed by Ekstróem and others, and in 5S. 
Peckii, as observed by Storer and myself, there is found a true 
marsupial pouch, consisting of two folds of skin, posterior to 
the anal opening of the male. These folds are directed in- 
wards, and meet on the median line. In this pouch the eggs 
are deposited by the female, and remain there till incubation 
1S complete, and even after the eggs are hatched the young 
return to the pouch as a place of refuge. 
In all of the preceding instances the fetus is developed 
exterior to or upon the surface of the body. The Pipe-fishes, 
Which are analogous to the Marsupials among Mammals, form 
ht wr interesting account of the nest-building of the Sticklebacks, see 
k Ann. g. of Nat. Hist. Vol. X. N. 8. p. 
T I have witnessed this habit in a pregnant female which was in my posses- 
, The eggs were deposited during the night, but on the following morning 
ined of their contents, the empty envelopes being seattered about 
bottom of the vessel. 
JOURNAL p, S. N, H, 56 NOVEMBER, 1854, 
