TEMPERATURE DURING TRANSPORTATION. 47 



moss becomes saturated. So long as the ice-water percolates 

 through the pads there is no danger, but if the ice becomes ex- 

 hausted, and the temperature rises, suffocation of the embryo will 

 certainly ensue. Under these circumstances it is frequently 

 advisable to send an attendant in charge of the consignment, 

 with orders to replenish the ice according to circumstances. In 

 the case of foreign journeys of short duration as, for instance, to 

 America or Newfoundland ova may either be packed dry, in 

 which case the air-tray is filled with sawdust to protect against 

 frost or moisture, or the air-tray being filled with pieces of ice 

 broken to the size of walnuts and rolled in sawdust, partly to 

 prevent them rattling about, but principally to ensure the ice last- 

 ing the ten or fourteen days occupied on the journey. 



Where eggs are to cross the equator, the foreign boxes require 

 to be placed in an ice-house and the ice-tray kept full of crushed 

 ice, so that the temperature of the moss may fall as closely as 

 possible to 32, while the temperature of the ice-house itself 

 should be kept below 46. 



I do not think it judicious to freeze ova, as although I have 

 several times successfully hatched a few eggs which I had pre- 

 viously frozen in air as a general rule, ova which have been once 

 frozen are useless. 



