[11 J OPERATIONS AT CENTRAL STATION. 889 



4. EMBRYOLOGICAL AND EXPERIMENTAL, INVESTIGATIONS. 

 A. — Professor Ryder's Investigations. 



In connection with the work of shad propagation at Central Station, 

 and during the progress of it, a series of interesting embryological stud- 

 ies were made by Professor Eyder. These embraced : 



I. — Observations on the mode of absorption of the yelk of the embryo 

 shad. 



II. — Notice of an extraordinary hybrid between the shad and striped 

 bass. 



III. — Cause of the non-development of fungus on the eggs hatched in 

 the McDonald jar. 



IV. — Experiments with carbolic acid to kill the fungus on large fishes. 



V. — Disturbance of the balance of conditions, and its influence on the 

 crustacean food of the shad. 



VI. — A means of demonstrating cartilage in fish embryos. 



VII. — Methods of handling white perch ova. 



VIII. — Notes on small fishes and water animals which prey on fish 

 larvfe. 



IX. — Observations on the food of the young Japanese gold-fishes. 



X. — Experiments in supplying the proper food for larval shad. 



XI. — Mechanical conditions afi"ectiug the development of fish ova. 



XII.— Specific character of protoplasm. 



A full account of these will be found in Bulletin of the United States 

 Fish Commission, Vol. I, p. 179. 



B. — Other Investigations. 



A number of experiments were instituted under my direction by Mr. 

 W. F. Page upon the eggs and fry of the shad with a view of deter- 

 mining the influence of different conditions upon the develojjment of the 

 eggs and the health of the fry. The results of these experiments as 

 reported by Mr. Page are herewith appended. 



No. 1. May 15. Held 25,000 young shad in asphalt can for seven- 

 teen hours without change of water. Afterwards shipped and deposited 

 in good order. Temperature of water at station 53° F. 



No. 2. May 16. Hatched 20,000 shad eggs over the oil stove (dark, 

 cloudy day), using a water bath to diffuse the heat. All hatched 

 in twelve minutes. Eggs were well developed, being in about twenty- 

 four hours of their time of hatching naturally. Fish were strong and 

 healthy, and were shipped on the following day by Mr. Newton Simmons 

 to Kentucky, who reported they traveled excellently well with no loss. 

 Temperature of water at station 53° F. 



No. 3, May 20—9 a. m. Put 20,000 shad in a wood-bound can. 

 Changed every three hours at 8 p. m. ; delivered to Baltimore and Ohio 

 Express Company, for shipment to Mr. Eugene Blackford, of Fulton 

 Market, New York City. Also 4,000 in a small half-gallon pail, under 

 same treatment, shipped at same time. A telegram from Mr. Blackford 

 on the following day announced that in the wood-bound can the fish 



