[23] - ARTIFICIAL PROPAGATION OF FISH. 513 
The means which have been recommended for transporting fish-eggs 
are very numerous. The one which recommends itself on account of its 
simplicity, and which is invariably successful, is to use flat boxes, meas- 
uring 10 to 12 centimeters in height, which have been previously fur- 
nished with a piece of moist linen or muslin, to spread the free eggs on 
them, and to cover them well. These pieces of cloth are moistened from 
time to time. Of late years cloth has been replaced by aquatic mosses 
(Sphagnum), between which the eggs are placed in layers. This way of 
transporting eggs will invariably prove successful if the eggs do not 
touch each other, and if the pressure of the upper or the lower layers of 
moss is not too great. 
As regards glutinous eggs, like those of the perch, it is reeommended 
to place them with some bunches of aquatic plants in glass globes about 
three-fourths full of water. Eggs adhering to foreign bodies, like those 
of the carp, should be wrapped with the bodies to which they adhere in 
moist cloths and be placed in a box or basket, on a layer of moist plants, 
in such a manner as not to bring any great pressure to bear on them. 
The forwarding of spawn in glass globes filled with water, which has 
lately been recommended by some, is fraught with great danger to the 
life of the embryo, and this method should, therefore, ouly be employed 
in the cases indicated above. The shell of the egg is easily broken by 
the motion of the water in the globe, and the germ is thereby destroyed. 
In all cases, and whatever means of transportation are employed, it is 
essential not to pack the eggs immediately after their feeundation. Ex- 
perience has shown that the most favorable time for transporting spawn 
is the period when the embryo is far enough developed to show the eyes like 
two black spots on the membrane of the shell.* 
The forwarding of fish is regulated by the age of the fish which are 
to be transported. The younger the fish, the easier it is to transport them 
a great distance.t Fish which have been recently hatched are inclosed 
in vessels filled with water, in which a few aquatic plants are placed. 
When still in the state of young fry they are placed in large buckets 
three-fourths filled with water, the motion of which is deadened by 
means of a board or a wreath of straw placed in the water. Spring or 
autumn are the seasons most favorable for transporting fish. 
In summer the heat and thunder-storms may kill the fish. If they 
. have to be transported during this season, they should be forwarded by 
night, and fewer fish should be put in the vessels. Care should be taken 
to keep the water constantly in motion, even when the vehicle convey- 
ing the fish stops. 
During long journeys it is necessary to renew the water from time to 
time, in such a manner as not to produce too great a difference of tem- 
perature between the old and new water. It is also necessary that air 
should enter the tubs at all times. 
*M. CostE: Comptes-Rendus, p. 109. tM. CosTE: Comptes-Rendus, p. 110. 
S. Mis. 29 33 
