X 



tliiit time, our operations were restricted a]iiK>st exclu- 

 sively within experimental limits. 



Prof. J^aircl, I". S. Commissioner of Fisli and Fisher- 

 ies, liaving kindly seiit with me Pi-of. John A. Ryder, a 

 young naturalist of thorougli training and exj^ert in 

 niicroscopic work, we were able to study the embryology 

 of the mackerel and porgy in a vej-y tln^rough and satis- 

 factory manner. The result of Prof. Ryder's investiga- 

 tions will be found in a pap^^r prejjared l)y him upon this 

 subject, and which will be published in Prof. Baird's 

 report to Congress. 



As the eggs of the mackerel, unlike those of the shad, 

 are somewhat lighter than Avater and manifest a conse- 

 quent tendency to Hoat upon the surface, the apparatus 

 used in the cultivation of shad cannot ])e efficiently em- 

 ployed in their manipulation. It is, therefore, necessary 

 that some other form of apparatus should be devised, as 

 that used in the shad -hatching operations is so con- 

 structed that a current of water flows in at the bottom, 

 buoying up the eggs, keeping theiii constantly in motion, 

 and momentarily bringing fresh particles of water in 

 contact with each egg. 



Such a current, eitlier in the conical vessels or in the 

 cylindrical plunge ()uckets —both of which forms of 

 ax)paratus have been described in previous reports — acts 

 ago. in Hi the gravity of the eggs of the shad -: but in the 

 case of those of the mackerel, and of all others that have 

 a tendenc}" to float, the current acts mitli such tendency 

 and causes the eggs to pile in masses at the surface of 

 the wat' r. ^;M;vel*al forms of apparatus, in which the 

 direction oi' tlie cu^.jent is reversed, have been experi- 

 mented Avith. and are found to act most satisfactorily. 



It is hoped that during the next season the work can 

 be conducted at the proper places and on a sufficiently 

 large scale to enable us to determine which form of the 

 vessels that have already ])een experinjented with can 

 be oijerated with the l)esr r*esults and with the greatest 



