PERITONEAL MEMBRANES, OVARIES, AND OVIDUCTS OF 

 SALMONOID FISHES AND THEIR SIGNIFICANCE IN FISH- 

 CULTURAL PRACTICES. 



By WILLIAM CONVERSE KENDALL, 

 Scientific Assistant, U . S. Bureau of Fisheries. 



INTRODUCTION. 



The observations embodied in the present discussion were begun several years ago 

 and have been carried on intermittently to the present time. The study has been 

 attended by various difficulties. It has been almost impossible to obtain perfectly 

 preserved specimens in which the internal organs had not been more or less deranged 

 or mutilated. The membranes in question, being very delicate, are easily torn or broken 

 in handling prior to or during dissection and are liable to disintegrate unless well pre- 

 served. These facts and others, together with erroneous ideas derived from published 

 references' to these structures, have occasioned many uncertainties which have taken a 

 long time to clear up. Since the ovaries undergo many changes of both external and 

 internal appearance, as well as of position, at no time in their growth or development 

 can they be said to be exactly the same as at any other time. After the ova are shed, 

 in those species which normally survive the spawTiing period, the ovaries undergo many 

 retrogressive changes. Furthermore, the conditions are not always uniform in the same 

 species. Somewhat different conclusions might be reached from observations upon 

 examples representing one or two periods of development only than from a more com- 

 plete series. Therefore it has required many individuals to permit of an exact determi- 

 nation of conditions. In fact it was only after careful dissection of more than a hundred 

 American smelts that one which seemed to conform to the conditions in the European 

 smelt, as described by Huxlty (1883), was found. Probably the failure of the anato- 

 mists, to whom reference is made in this paper, to recognize the conditions which are 

 herein described, is attributable to some such facts as the foregoing. 



As this paper is primarily intended for fish-culturists and those unfamiliar with 

 anatomy, definitions of the principal abdominal structures precede the discussion. 

 Although desirable, it has been impossible to entirely eliminate scientific phraseology. 



At the end of this paper is given an alphabetical list of the authors and works con- 

 sulted. In the te.xt of this discussion these works are referred to by author and date of 



publication. 



ABDOMINAL VISCERA. 



The abdominal viscera comprise the greater portion of the alimentary tract, secre- 

 tory, excretory, and reproductive organs, together with certain nervous and vascular 

 connections. The present discussion is principally concerned with the supporting and 



