194 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



was reached, and at this depth the bottom consisted of fine, soft mud. 

 While ou the east coast spawniug-grouuds, examined during the autumn, 

 the surface temperature in most cases varied from 53° F. to 55° F. and 

 the bottom temperature from 52° F. to 54° F., even at a depth of 40 

 fathoms ; the temperature at the Ballantrae bank varied from 42o.8 to 

 430.8 F. at the surface, and from 42o.8 to 43o.5 F. at the bottom. The 

 corresponding surface temperature, however, on the east coast during 

 the week ending March 8 was from 2° to 3° F. lower than at Ballantrae. 



According to previous observers: 



" When spawning takes place naturally the eggs fall to the bottom 

 and attach themselves. But at this time the assembled fish dart wildly 

 about and the water becomes cloudy with the shed fluid of the milt. 

 The eggs thus become fecundated as they fall, and the development of 

 the young ova sticking to the bottom commences at once." 



Mr. Mitchell, in his book on " The Herring," referring to the once 

 famous spawning-bed off Dunbar, states that — 



"About August 30 the shoals began to deposit their spawn a short 

 distance from the harbor, and on September 3 the fishermen found that 

 a very large body of herrings remained fixed to the ground in the prog- 

 ress of spawning, the ground being of a rocky or stouy nature." 



While many tisheimen believe that herring spawn on hard ground, 

 some believe that they also spawn on a clayey bottom ; and while some 

 think that they spawn near the bottom, others affirm that they spawn 

 near the surface. Having secured at Ballantrae a large number of live 

 herring, some of the largest and ripest males and females were placed 

 in a large wooden tank into which a number of stones and a quantity 

 of sea-weed had been previously introduced. After the fish had been 

 about two hours in this tank the stones and sea-weed were examined. 

 Although a few eggs were attached to both stones and sea-weed it was 

 quite evident that the eggs had not been deposited in the same way as 

 those found on the stones dredged on the previous day; but we were 

 not surprised that only a few isolated eggs were found on the stones, 

 because the fish had been disturbed every few minutes by the pouring 

 of water into the tank. 



On reaching Eothesay the hatching-boxes and live herring were at 

 once transferred from H. M. S. Jackal to the tanks — a tank into which 

 comparatively little light entered having been selected for the ripest 

 and most vigorous herring. In about half an hour after they were intro- 

 duced a large, full herring was seenmovingslowly about the bottom of the 

 tank, with four other fish making circles around her at some distance from 

 the bottom. Appearing satisfied with a particular stone which she had 

 evideutl.v been examining, she halted over it and remained stationary for 

 a few minutes about half an inch from its surface, the tail being in a 

 straight line with the tank and the pectoral fins near or resting onthebot- 

 tom. While in this position a thin, beaded ribbon was seen to escape 

 from the genital oi)eniug and fall in graceful curves ou the surface of 



