lioyal Sociehj of Edinburgh. 75 



the subject, is corroborated by the examination of the stomach and 

 intestinal canal of the herring, and the stomachs laid on the table of 

 the Society. 



3. Food and Reproduction of the Salmon (Salmo Salar, Linn.). The 

 author stated on this head what had been remarked by the most 

 esteemed authors on natural history to form the food of the salmon ; 

 and exhibited preparations by Dr. Pownell confirming the statements 

 of these writers. He next noticed the valuable evidence taken before 

 a Committee of Parliament in 1824-25, regarding the food and na- 

 tural history of the salmon, which also corroborated the statements 

 of systematic writers ; and remarked, that when these fishes prey upon 

 animals in roe, such as the Asterias, the ova often remain in the 

 stomach and intestinal canal after the other portions of the food are 

 wholly digested. He next gave an abstract of the evidence laid be- 

 fore the Parliamentary Committee as to the periods of the ascent of 

 the salmon in the different rivers for the purpose of spawning and the 

 descent of the fry to the sea ; and pointed out the experiments made 

 on the development of the ova by Mr. John Hogarth, jun., in the 

 Appendix to the Report of the Committee, and those detailed by 

 Mr. Schonbergin Sir David Brewster's Journal of Science. 



Dec. 18, 1837. — Dr. Hope, Vice-President, in the Chair. 

 Experiments on the Growth of the Fry of the Salmon, from the exclu- 

 sion of the Ova to the age of seven months. By Mr. John Siiaw. 

 Communicated by Mr. Stark. 



The author of this paper had formerly made experiments on the 

 growth of the salmon fry, by procuring spawn from the river bed 

 where it had been deposited by the salmon. Not considering these 

 experiments, however, as entirely unobjectionable, he procured two 

 fishes from the river Nith in the act of spawning ; and having ex- 

 pressed the ova of the female in a convenient place, the milt of the 

 male fish was made to impregnate them as nearly as possible in imi- 

 tation of the natural process. The ova were then placed in ponds 

 prepared for the purpose, and so arranged as to exclude all chances 

 of error as to the species or the nature of the progeny. The ponds 

 were two in number ; one twenty- five by eighteen feet, the other fifty 

 by thirty feet, and two feet deep. The bottom was thickly imbedded 

 with gravel ; and a small stream of spring water entered the ponds 

 at the upper corner, and escaped by an opening at the other end. 

 Both apertures were covered by a wire grating. The ova in one ex- 

 periment were deposited on the 20th of January 1 737. On the 10th 

 of March (fifty days after deposition) the embryo fish were visible. 



