496 | REPORT OF COMMISSIONER OF FISH AND FISHERIES, [6] 
manipulation is also necessitated by the circumstance that the milt of 
most fish loses its fecundating property very soon when brought in 
contact with the water. The same applies to the eggs, which when 
first laid are united and surrounded by an alinost invisible mucilaginous 
covering. When brought in contact with the water this covering be- 
comes bloated in a few seconds: the fecundating spermatozoa can no 
longer reach the egg, and are thus, by the sheer force of circumstances, 
prevented from performing successfully the process of fecundation. It 
appears that the substance which unites and envelopes the eggs acts 
in the same manner as the spawn of frogs which, according to experi- 
ments made by Messrs. Prévost and Dumas, cannot be fecundated as 
soon as the glutinous matter which envelopes it has become bloated 
by water. 
§ 3.—Artificial fecundation of eggs which adhere to neighboring objects. . 
In order to accomplish the fecundation of eggs of fish like the carp, 
gudgeon, barbel, &c., which, by means of a glutinous matter, attach 
their eggs to any objects near them, the above-described practiée must 
be somewhat modified. One takes a small quantity (a few handfuls) of 
well-washed aquatic plants, such as the water ranunculus, vessels of the 
form and size above described, and a trough. Three persons must as- 
sist at this experiment; one takes the female fish and relieves it of its. 
_ eggs in the manner described above, another takes the male fish and 
extracts the milt, whilst the third stirs the water with a small bunch 
of herbs and thus facilitates impregnation. The eggs, which are of a 
viscous nature, adhere to the plants, and when these are sufficiently 
charged with them, one lets them lie in the spermatized water for three 
or four minutes in order to give them time to absorb the fecundating 
molecules. In order that the eggs adhering to the bunches of plants 
may not dry, these bunches are gathered in a trough, where they are 
covered with pieces of wet cloth. This manipulation does not offer as 
many difficulties as the preceding one, but it nevertheless requires con- 
siderable attention. Thus it is essential to allow only a quantity of 
eggs proportioned to the surface which one desires to cover with eggs 
to fall in the vessel; otherwise they would become conglomerated on 
the plants, which would be very detrimental to their development. 
If there is no other way, two persons may go through this operation. 
In that case one will extract the eggs whilst the other gathers them on 
the bunches of herbs. When the eggs have become attached to the 
plants they are placed in a vessel to be subjected to the influence of 
the milt of the male fish. The water is gently stirred with the plants 
in order to subject aJl the eggs to the influence of the fecundating liquid. 
After the bunches of plants with the eggs have remained in the water 
impregnated with milt for 5 or 6 minutes the operation is finished, and 
the eggs are put away for the purpose of being hatched, either in an 
