GROWTH OF THE FISH IN OVO. 183 



or eggs of that part of it nearest to the vent will 

 always be found of larger size, and softer than 



towards perfection. At the expiration of sixty-three days 

 the formation exhibits at one of its extremities two very 

 small black spots, which afterwards become the eyes of the 

 fish. A decided change now takes place daily ; the young 

 fish are getting larger — the black spots are becoming more 

 visible — and the brilliant red, which at one time nearly 

 covered the yolk, drawing closer towards the fish, arid 

 leaving the other parts of the egg of a paler appearance, 

 and the fish fully double the thickness that it was on its first 

 appearance : the shell of the egg appears thinner and more 

 transparent, so as to afford full opportunity for minute in- 

 spection. At seventy-nine days all the above appearances 

 are more marked, and at ninety-three days the shell of the 

 egg is a good deal distended — the head of the fish larger 

 and better formed — the eyes more visible — and the red. of 

 the yolk leaving the back parts and drawing more closely 

 towards the belly of the fish, where it appears to be formed 

 into a conical-looking bag, one end of which is attached to 

 the fish. This appears more clearly after the ova have been 

 deposited 100 days in the gravel, for now we see the em- 

 bryo fish alive — we see it turning over within the shell of 

 the egg, the shell being very thin and much distended — 

 the red appearance in the yolk is now fully formed into a 

 conical bag attached to the neck and belly of the fish ; and 

 as it turns over within the shell we see the little bag turn- 

 ing with it. If a single ovum at this stage is taken with a 

 little water into the hollow of the hand the water's temper- 

 ature is augmented, and the movements of the fish so much 

 expedited as to enable us to see all the difierent parts of 

 the fish-formation, and to aiFord us time to note all the 

 various alterations, which are now neither few nor small. 

 N 4 



