ARTIFICIAL PROPAGATION" OF TROUT. 21 



vent. With the thumb and forefinger he then gently presses out the 

 eggs, beginning the pressure just forward of the vent. The hand is 

 then moved forward toward the head of the fish, and further gentle 

 pressure is applied as necessary to assist the natural flow of eggs 

 until all that will come freely from the fish are obtained. Pressure 

 should never be applied forward of the ventral fins, as even slight 

 pressure applied over the vital organs is very apt to result in injury 

 to the fish. The above seems to be the logical and rational method of 

 spawn taking, as the egs nearest the vent are taken first, leaving a 

 clear passage for those that follow. 



As the eggs fall into the dampened vessel milt is immediately 

 applied, being obtained by the manipulation of the male fish in a 

 similar manner. The next step is to add enough water to cover the 

 eggs and agitate the vessel sufficiently to thoroughly mix eggs and 

 milt, or a feather may be used to effect the mixing prior to the in- 

 troduction of water. The excess milt is then almost immediately 

 discarded by adding and pouring off' water until it becomes clear, 

 when the vessel is half filled with clean water and is protected from 

 temperature changes by placing it in running water or inside of a 

 larger vessel of water. It is then left entirely unmolested until the 

 adliering stage has passed and the eggs separate, the time required for 

 separation being from 30 to 60 minutes, according to the temperature. 

 Some spawn takers consider it advisable to delay washing the eggs 

 until after separation occurs, while others use no water at all until 

 that stage is reached. In general practice, however, the method 

 herein described is most satisfactory. If the eggs remain in the 

 vessel long after separation, the water must be changed frequently. 



The work of spawn taking should be done only by thoroughly ex- 

 perienced persons. While the test of efficiency along this line is fre- 

 quently based on the percentage of fertile eggs obtained, the numbers 

 of fish stripped and not injured is a point of equal importance. 

 Proper metliods of spawn taking carefully applied will result in no 

 injury to the adult fish, either females or males; but unless the 

 spawn taker understands something of the anatomy of the fish and 

 exercises the utmost care serious, if not fatal, injuries are very likely 

 to be inflicted. Some of the more common mistakes made by spawn 

 takers in handling fish during the egg-taking process are mentioned 

 below : 



Grasping the fish by the tail and holding it head downward while 

 it struggles violently, or similar handling in a dip net. Such treat- 

 ment is very apt to result in rupture of the delicate ova-containing 

 membrane, causing the eggs to fall into the abdominal cavity, from 

 which they can not be extruded. An injury of this nature may 

 result in barrenness or even death. The proper method of remov- 

 ing a fish from the water is described under the section on rainbow 

 trout. 



After stripping a fish spawn takers sometimes throw it from a dis- 

 tance into the retaining inclosure or pond. This procedure is so ob- 

 viously wrong that it should need no comment. Perhaps the most 

 common cause of injury in spawntaking is the practice of certain 

 spawntakers of squeezing the fish several times, beginning well for- 

 ward near the gill opening, until blood and fecal matter are ex- 

 truded, in order that every egg may be secured. This is sure to re- 



