282 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



5. A section of the intestinal canal, cut from a point below the open- 

 ing' of the coecum nearest the termination of the alimentary tube, spread 

 on glass. It exhibits on its mucous membrane an inspissated matter of 

 a somewhat darker brown color than that of No. 3, and the debris of 

 microscopic shells, small enough to i)ass the pylorus, but too large to 

 enter the mouths of the coeca. 



C. A wet preparation of the gullet, stomach, c<Bca, and intestine. 



7. A preparation in ether of the cceca, their orifices, and the intestinal 

 exp.ansion in which they open. 



8. Several dried stomachs (some of the last obtained) unopened, but 

 supposed to contain the fuci and infusoria described. 



The most important of the specimens have been placed in the hands 

 of Lieutenant Holt, U. S. A., who has kindly undertaken to deliver 

 them to Dr. Walter F. Atlee, of Philadelphia, to be presented by him, 

 with this monograph, to the Academy of Natural Sciences. 



[An abstract of this paper will be found in the December number 

 (1860) of the Proceedings of the Academy of N. Sciences of Philadel- 

 I)hia, appended as a continuation of the report from the Biological De- 

 partment of the Academy for May, 1860. By reference to this report 

 it may be se^n that the statements made in relation to the contents of the 

 stomachs and the cwca were abundantly verified by members of the Acad- 

 emy in the specimens mounted for microscopical examination which 

 accompanied this paper.* 



Before the shells of the minute organisms can be easily recognized, 

 the solid contents of the stomach should be thinly spread on glass and 

 thoroughly dried, in order to remove the liquid matter which renders 

 these small objects obscure. With specimens thus i^repared from fish 

 fresh run from the sea during the spawning season, examined under a 

 bright sunlight, the investigations detailed in this i)aper may be easily 

 repeated. 



Mobile, Ala., October 25, I860.] 



TBLE imCROPYliE OF THE ECJCJ OF THE 1VHITE PEKCH. 



By JOH]\ A. KYDER. 



[Letter to Professor S. F. Baird.] 



I have found the micropyle of the egg of the white perch; it measures 

 .0075 millimeter or -g^^Va iiich in diameter. Average diameter of egg, -^ 

 inch; of oil sphere, y^o inch. 



Washington, D. C, 3Iay 17, 1881. 



* As the vegetable matter in the stomach of the fish is in a disintegrated state, a lens, 

 generally, is required to determine its nature. 



