44 



food. High temperatures, lack of moisture, and concus- 

 sion are the principal, if not the only, causes of injury to 

 the embryo. 



It is my present ojnnion that concussion is more imme- 

 diately fatal than a high temperature; it kills within a 

 few days. Lack of moisture is shown at once by indented 

 eggs, and upon the degree of indentation rests the damage. 

 I have experimented with such eggs, and have found that 

 those only slightly indented have produced fairly good 

 fish, while others somewhat dryer did not. A high tem- 

 perature on eggs of Salmonidce — and it is of these that I 

 speak — makes weak embryos, if they live to break the 

 shell. They hatch head first, and all fish culturists know 

 that such fish have a small chance for life, or, that they 

 have not strength enough to straighten from the coil in 

 which they have been, and are ''whirligigs," spinning 

 round in one direction at every effort to move. These die 

 of starvation because they cannot swim. 



A lot of salbling eggs received from Germany a year 

 ago looked first-rate, but one-fifth of the embryos had not 

 strength enough to straighten after hatching, the cause 

 being a high temperature through lack of ice in the pack- 

 ing, which was my own " wet" method. This is the main 

 risk in this method, while the " dry " packing is all risk. 

 I know by letters received that many eggs are j)rematurely 

 reported to be good, i. 6?., because they are not dead, and 

 that the injury to an indented Qgg is not taken into con- 

 sideration by some fish culturists ; hence I write of it, 

 although aware that there are men at this meeting who 

 understand this source of injury to a fish-egg, but it is not 

 for them that this is written. Another result of high tem- 

 perature, en roiite^ is a softening of the egg, either the 

 outer covering or some part beneath, and these embryos 

 hatch, but do not live to take food. 



I have seen soft trout-eggs which seemed to have cast one 



