flow to obtain it. 189 
Then, again, care has to be taken as to the moss that is 
used. It must be perfectly fresh and in growing condition. It 
has been noticed that when the moss goes bad or ferments the 
eggs in that tray are all dead. When it retains its vitality, and in 
reality grows a little, the eggs travel well, other things of course 
being equal. The ice in the uppermost tray melts slowly, and the 
water percolates through the moss in the trays beneath. But for 
the ventilation given, the delicate embryos would be in great 
danger of drowning. It was found for some time that the eggs in 
the bottom tray suffered the most, and were often in bad condition. 
On this account an air space was left at the bottom, and this also 
serves as a temporary receptacle for the water caused by the 
melting of the ice above. This water does not remain here, 
however, but escapes through a hole in the box bottom, and the 
box itself stands on a couple of wooden slats, one on each side, 
which act as feet and allow the access of air, and the same time 
the escape of the water. 
The eggs may be packed between layers of woven fabric or 
of mosquito netting, but this is in itself a source of danger, as 
decay sets in, and affects the vitality of the embryos. It may not 
prevent the eggs hatching, and in some cases may not do them 
harm, but they remain in a more healthy state during long 
voyages, when packed between layers of felted moss only. The 
unpacking is a little more difficult, but the eggs turn out better, 
and after all, with a little practice in unpacking, there is no 
difficulty. The two layers of felted moss are kept apart by the 
eggs which lie between them, and are therefore easily separated. 
After lifting the top layer of moss a piece of linen fabric may be 
laid over the eggs. The tray may then be inverted, and the eggs 
will mostly remain on the cloth when the tray with its contents is 
righted again. Any remaining eggs may be feathered, or other- 
wise picked off. Should a layer of felt fall to pieces during 
unpacking, as may easily happen, it is readily separated from the 
ova when all are placed in a bowl of water, as the specific gravity 
varies considerably. The eggs will go to the bottom of the bowl, 
whilst the particles of moss are held for a time in suspension in 
the water, and may be poured off with it, and then a little more 
water added and poured off again, the process being repeated 
