[37] NUTEITIVE VALUE OF FISH AND INVERTEBRATES. 469 



the shells for analysis, less was allowed to escape than is generally the 

 case in the commercial process, I think, so that the specimens opened 

 at the laboratory had doubtless a larger proportion of liquids than oc- 

 cur in those ordinariiy found in the markets. This seems to be the ex- 

 planation of the fact that the shell contents of the oysters received in 

 the shell at the laboratory had larger proportions of ash than were 

 found in the so-called "solids," as purchased of the oyster dealers. 



The last two columns of Table VII need a word of explanation. They 

 give the amounts of "edible portion" and "actual nutrients" in the 

 whole specimens. In the case of oysters, for instance, the majority of 

 the specimens were received in the shell. The percentages of edible por- 

 tion — shell contents, flesh and liquids together — was of course small j 

 that of water-free substance, which constitutes the nutritive material 

 of the shell contents, was of course much smaller. If the mineral mat- 

 ter of the salt water were subtracted, as was not done, the amount of 

 actual nutrients would be smaller still. If, however, the specimen con- 

 sisted of the shell contents simply, of course the percentage of edible 

 portion would be 100, and that of nutrients correspondingly large. In 

 the lobsters, crabs, turtle, &c., the edible portion and nutrients are 

 determined and stated in the same way as in the mollusks. 



Tables VII to X are, I think, sufficiently explained in the text with 

 which they are incorporated. They are derived from Tables II- VI. 



Table XI is also explained in the text. The figures for meats, dairy 

 products, &c, are, with the exception of some from European sources, 

 and indicated by italics, compiled from the results of the analyses re- 

 ferred to in the beginning of this article as undertaken in behalf of the 

 Smithsonian Institution (National Museum), but as yet unpublished. 

 Those of fish, invertebrates, &c., are selected from the tables which I 

 have just described. The minor differences between some of the figures 

 for invertebrates, especially in this and the preceding tables, are due to 

 the fact that, since this table was put in type, the former tables have 

 been revised and slight changes introduced. Thus, in the revision, 

 for " oysters best " a different specimen was selected from that whose 

 composition had been given in Table XI. Of course, such matters as 

 this are of small moment, and demand only a passing notice provided 

 the analyses are in themselves correct. 



Table XII. Analyses of vegetable food. — The reasons for inserting 

 this table here are, that it is interesting for comparison with the fish and 

 other animal foods and that some of its figures are used for data in com- 

 puting the costs of nutrients in the section on the economic application 

 of the analyses. 



