HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Winkler, L. R. Articles by Wagner, E. D. Search for Related Content PubMed PubMed Citation Articles by Winkler, L. R. Articles by Wagner, E. D.

A Method of Comparing Geographically Distant Snail Populations by Study of Their Shell Composition¹

Edward D. Wagner
Department of Microbiology, School of Medicine, College of Medical Evangelists, Loma Linda, California

1) The percentages of organic matter in shells of laboratory-raised Oncomelania nosophora and in those of their field counterparts were determined by both individual and bulk methods.

2) Simple chemical analyses indicated considerable nitrogen and some amino acids present in the organic material of the shells.

3) Shells of laboratory-raised snails contained only about one-half as much organic matter as those of field snails.

4) It is thought that this indicates a possible insufficiency of nitrogenous food in the laboratory culture dishes. This may be due in part to an excess eating of refined cellulose.

¹ It is recognized that some unavoidable variables may have been present in the material at hand. This necessitates the emphasis being placed upon the method rather than the results obtained.