784 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [2] 



but that when it falls to 29° they all die, apparently through actual 

 freezing. It has several times occurred at the Wood's Holl Station 

 that all the adult fish on haud have died in this way in a single night. 

 At the suggestion of Captain Collins, it was determined to attempt the 

 collection of eggs directly from the fish on the fishing-grounds and 

 transfer them to the Wood's Holl Station by rail. Mr. George H. Tol- 

 bert was sent from Washington charged with the manipulation of tho 

 eggs ; and, with the assistance of the officers and crew of the Grampus, 

 he collected and transferred all the eggs obtained after the 25th of 

 January. 



In an ordinary season the weather and other circumstances would be 

 much more favorable to the capture of codfish than the winter of 18S6- 

 '87, and there would be no great risk attending their transfer from the 

 Gulf of Maine to Wood's Holl up to the 1st of February. It might, 

 therefore, be reasonably expected that a sufficient stock of breeding 

 codfish could be gathered at Wood's Holl before the end of January 

 to supply all the eggs that could be profitably incubated there. 



The fish brought in by the Grampus were taken from her well in fairly 

 good condition and placed in cars in one of the basins at the station. 

 On the approach of dangerously cold weather in the winter an inclosure 

 was made in the basement of the hatchery and the fish then on haud, and 

 afterwards received, were placed therein. The experience of a single 

 winter seems to warrant the belief that in such an inclosure fish will be 

 safe from freezing in the severest weather. 



The fish were overhauled from time to time, generally at intervals of 

 two to four days, and the spawn and milt extruded into large pans con- 

 taining a little sea -water, from which they were in a very short time 

 washed off and placed carefully in the hatching-jars. The total num- 

 ber of gravid females found duriug the season was 108, and their aver- 

 age yield of eggs was about 300,000 each. 



The first lot of eggs, taken on the 18th of November, began to hatch 

 on the 2Gth, eight days from impregnation. The temperature of the 

 water, which up to this time had been above 50°, fell steadily, until, on 

 the 19th of January, it reached 32° Fahrenheit, the lowest reached in 

 the hatchery duriug the season. The development of the spawn was, in 

 consequence, so retarded that the lots taken in January and February 

 were from twenty to twenty-five days in incubation. The best success 

 attended the incubation of the eggs that were taken from the fish at 

 the station in December and January. In several lots as high as 85 

 per cent, of the eggs put into the jars were successfully hatched, and in 

 most cases all of the fry were liberated alive. Some of the lots of those 

 months were, however, less satisfactory, the ratio of fry hatched being 

 in some cases as low as 50 aud 40 per cent., and the results obtained 

 from those taken in jSTo\ ember, and from those taken at sea and brought 

 overland to the station in February ami March, were even less satisfac- 

 tory. From 11,150,000 transferred overland, but 722,500 were hatched. 



It is a matter of common experience among fish-culturists that the 



