ALASKA FISHEKIES AND FUR INDUSTRIES, 1911. 81 



operator's fingers are inserted into the abdominal cavity genUy to 

 assist in removing any eggs that may be enfolded in the o-rgans or 

 that may merely adhere to the walls of the cavity. Fertilization is 

 accomplished m the usual manner. 



Care must be exercised not to tear loose from the ovaries any eggs 

 that do not come freely when the organs are movecl from side to 

 side by the fingers. Eggs thus torn loose are immature, and if taken 

 it becomes necessary to eliminate them subsequently in the hatchery. 

 It is preferable also to have the fish either m a vertical position or 

 with the head considerably higher than the tail, that gravity may 

 assist the flow of eggs. 



It was at first thought necessary — and the practice still obtains 

 at some stations — to bleed the fish either by cutting off the head 

 or tail before making the incision. Experimentation, however, has 

 conclusively demonstrated that no advantage results from this pro- 

 cedure, as the few drops of blood that may occasionally fall into a 

 pan of eggs result in no harm. The extra labor involved in bleedmg 

 may therefore be dispensed with entirely. 



Wlien taken by the method of incision the eggs are of greatly 

 improved quality; there is no straining or rupture of good eggs as 

 is inevitably the result when heavy hand pressure is exerted; no 

 unripe eggs are torn from the ovaries; and at the same time there is 

 no waste of good eggs left enfolded in the organs, as is certain to be 

 the case in strippmg by hand. The improvement in quality is 

 from 5 to 10 per cent and the saving in labor, too, is of noteworthy 

 consideration. 



The taking of Pacific salmon eggs by incision marks so distinct 

 an advance in fish culture that it is no longer permissible to continue 

 the obsolete method of stripping by hand. 



PREVENTION OF LOSS BY CONCUSSION. 



Coincident with the absorptive period in salmon eggs is an adhesive 

 stage varymg with the temperature from one to two hours, when 

 the eggs are exceedingly sensitive. This is the so-called period of 

 water hardening. Under no circumstances should the eggs be 

 handled during this stage, nor should they be subjected to the 

 slightest concussion. Repeated tests have demonstrated conclusively 

 that even allowing the buckets containing the eggs to stand on the 

 same platform where spawning operations are being carried on 

 results in considerable loss. 



To guard against this, the buckets should either stand on the 

 bottom of the stream or else on a platform in every way independent 

 of and having absohitely no connection with the main platform. 

 To some this may seem like a small and irrelevant consideration, 

 but strict observance is certain to reduce the loss by at least 2 or 



