18 REPORT OP commissioner OF PISH AND FISHERIES. 



Lot J) consisted of 109,000 eggs, yielded by two females taken in the 

 trap net of Mr. Bennett, Jnne -<>. Sperm and ova mixed at 5.15 p. m. 

 All of the eggs were fertilized and in the 4-eoll stage when examined 

 on board the ship shortly alter 7 p. in. All were placed in a McDonald 

 cod-box, in which they floated buoyantly in water of a density of 

 L.0221. The eggs were, allowed to remain without, ohange all through 

 the next day and until the morning of Jnne 28, when, at the age of 40 



hours, they were approaching the period of development when, accord- 

 ing to previous observations, they might be expected to pass into sus- 

 pension. Up to this time the mortality had been very small, and was 

 chiefly the result of eggs having adhered to the somewhat rough 



wooden sides or the coiners of the McDonald boxes, when they were 

 left high and dry by the receding water and killed. 



At 11 a. m. on June 28, at which lime the blastopore had just closed, 

 three lots of eggs, estimated to contain 25,000 each, were removed from 

 the McDonald box and subjected to the following conditions: One lot, 

 designated as sublot DA, was placed in a, second McDonald box under 

 conditions precisely similar to the first, and was retained as a check on 

 the other SUOlotS. 



A second sublot, designated as />/>', was placed in an apparatus 



designed to imitate the Chester t idal boxes and jar, arranged by cutting 

 t he bottom out of a 2-quart Mason butter jar, tying cheesecloth over both 



ends, and placing this upright in a pail provided with a siphon hose. 

 The eggs were placed within the glass cylinder in water which had been 

 gradually increased in density, and the apparatus then supplied with 

 water, the density of which had been raised by adding a solution jf 

 rock salt to L.0252, this having been previously determined to be the 

 density in which the eggs would just float at this period of their devel- 

 opment. About 500 gallons of this density of water, sufficient to till 

 one of I he large deck boxes, was made up to supply the. apparatus. 



After the height and rate of the tidal How had been adjusted to that 

 onstomarily adopted for the McDonald boxes, the apparatus was left 

 to itself, except that it was necessary to replace the water in the supply 

 tank and aerate it about every L2 hours. 



The third snblot, designated l>(\ was also passed gradually into the 

 water of L.0252 density, and then placed in a bos provided with cheese- 

 cloth bottom, which was floated in the supply box of high-density water 

 OH deck. 



The history of these three sublets briefly told is as follows: During 

 the next ,24 hours, those comprising DA had gradually set tied, becom- 

 ing distributed all through the water and on the bottom, although the 

 density had increased to L.0226, The eggs were alive and the oil- 

 sphere had begun to be absorbed. I n sublot />/>' the eggs all floated 

 in a compact layer at the surface of the water. They were slightly 

 more advanced in € velopment than DA and the oil drop was smaller. 

 Of sublot DO many of the eggs had been killed by rupture of the mem- 

 brane or other injury caused by striking or sticking to the sides of the 

 box while washing to and fro in the tank. 



