ON THE TRANSPORTATION OF SHAD. 367 



In the fresh-water temperature tests, the fish did not endure as long 

 as in the sea-water test, No. 4. 



There is ample evidence in the experiences in the treatment of shad 

 that they are in need of food when about six or seven days old, and if 

 not supplied will starve to death in from 70 to 80 hours, so that it is not 

 possible to say that the presence of the sea- water in the last test killed 

 the shad. No practicable methods for feeding embryo-shad and white- 

 fish (Coregonus albus) have been discovered, though river-water seems 

 to afford them some supplies of nourishment.* The intestines of many 

 of the embryo-shad from the jars, when examined under the microscope, 

 failed to discover auy food. 



The problem of the transportation of embryo-fishes like those of the 

 shad and white-fish (Coregonus albus) long distances, which occupy a 

 period of time longer than a week, requires study and experiment. The 

 probability is that the great need is some method for feeding them 

 en route. 



To devise a method for feeding them will require the services of a 

 microscopist familiar with the lower forms of invertebrates and the eggs 

 and larvae of higher groups, which are the principal minute organic 

 forms available as food in the waters where the fish breed naturally. 

 The only investigations which I am aware of are the observations of 

 Mr. S. A. Briggs, of Chicago, published on page 57 of the report of 

 1872-3, and those observations just referred to in these experiments. 



The experiment may also be carried out empirically by trying young 

 fishes with the different forms of the groups just referred to. If food 

 can be found among these forms, experiments as to the feasibility of 

 breeding them en route will be in order. Many of them have been de- 

 veloped in numbers by naturalists for purposes of study, and with some 

 it is very easily accomplished. 



Another, and probably the most feasible method to obviate starva- 

 tion, is, in the case of the shad, to retard the eggs by cold, and devise a 

 process of hatching en route. If this can be accomplished so that the 

 fish can emerge from the egg when six days out from land, they will be 

 likely to arrive at their destination with vigor and strength. 



These facts and experiences in regard to keeping shad alive seem to indi- 

 cate that the application of sea-water with a very gradual increase and 

 in small proportions has not a sensibly injurious effect. Where fresh 

 water has been used, no greater periods of life have been attained when 

 the fish were confined in small vessels. Still, the series of experiments 

 indicates that in proportion as the quantity of sea-water increases the 

 endurance of the fish diminishes; and, inversely, the less and more 

 gradually the sea-water is applied, the longer the fish endure. A paral- 

 lel instance would be that a little overplus of oxygen in the atmosphere 



"See report of United States Commissioner of Fisheries, 1872-73, p. 57; and fourth 

 annual report of commissioners of New York, 1872. p. 20. 



