530 NATURAL HISTORY OF AQUATIC ANIMALS. 



ing the spawn. Two tanks of about five feet diameter were placed at the edge of the shore and 

 partly tilled with water. As soon as the bag of the seine was on the beach the men picked up 

 the White fish and put them immediately into the tanks. The pans for impregnation were close 

 at hand, and as one man lifted the fish above the water in a dip-net, another took it from the net, 

 and with his right hand over the head of the fish and his left around the tail he held it over the 

 pan, standing at the left of the operator. The left hand of the operator was put against the back 

 of the fish and the right hand used in manipulating the abdomen. It was found that to induce 

 the eggs to flow freely from a fully ripe female, all that was necessary was to apply a gentle press- 

 ure just behind the pectoral fins, just where the nudging and bunting of the head of the male 

 fish is applied while racing her through the water. Not until the greater part of the free eggs had 

 fallen into the pan was it necessary to slide the hand along the abdomen. The free eggs came 

 away in a steady, liquid stream, but from a fish partially ripe their extrusion was slow, and in 

 masses comparatively dry that did not freely disengage themselves from the fish and fall into 

 the pan. 



" The female exhibited the most indications of pain when the pressure was applied in the 

 vicinity of the ovipore. The milt from the male will flow in from one to three jets by pressure in 

 the vicinity of the anus. 



" The method employed by Mr. N. W. Clark was that which was original with Mr. Seth 

 Green, using the smallest quantity of water possible. The eggs, after falling into the pan, and 

 the milt, having been stirred up with the water, were allowed to stand about half an hour, when 

 the milt, and water were poured off and the eggs carefully rinsed through several changes of 

 water. A small quantity of water was left with the eggs when they were perfectly clean. By 

 repeated actual 'counts, and by arranging on a plate in a true square, it was found that a large 

 tablespoon, moderately heaped up, contained about a thousand eggs. Eight ripe white-fish eggs 

 will lie entirely within the space of an inch, and the ninth will lie partially across the line. 



"A pat of moss was then put into the cups, and a piece of canton flannel, cut into the form of 

 the Swiss cross, after thorough saturation with water, was pressed lightly down into the cup, and 

 a tablespoonful of eggs poured upon it. The canton flannel was used to line the sides of the 

 boxes, because it was found that the contact of the zinc was fatal to the eggs, probably from the 

 poisonous elements of the oxide. The patch of canton flannel proved to be a great convenience in 

 taking out the eggs, as all that was necessary was to take the edges lightly in the fingers and 

 remove it from the box, and dipping the cloth with the eggs into a pan of water, they were 

 rinsed off with a few quick motions, without any tedious picking and rinsing the eggs free from 

 particles of moss. In arranging the eggs for transportation for a short distance, the use of the 

 cloth patches is undoubtedly a good method. After filling the boxes they were placed in the 

 trays, and the trays adjusted within the zinc can, when water was poured on until the whole con- 

 tents were thoroughly saturated, when the lid was closed and locked and the case was ready for 

 transportation to the hatching house. A small fee to the baggage-master excites considerable 

 interest in the safe-handling of the box. 



"Two trips were made from Ecorse to the hatching house at Clarkston, and about 1,330,000 

 eggs were put into the troughs, Mr. Clark having increased the number of troughs to fifty for the 

 purpose of receiving the extra supply of eggs. One half of the eggs were the property of the 

 commission, the other half to be controlled by Mr. J. P. Clark, of Detroit, Mr. George Clark, of 

 Ecorse, and Mr. N. W. Clark, of Clarkston. The eggs received attention from the second day 

 after they were placed in the troughs until about the middle of January, the eyes of the embryo 

 then showing distinctly, and the subsequent loss being very small. 



