200 American Fisheries Society 



To gain a clear insight into these matters, we must com- 

 pare the quantities of the various materials actually pres- 

 ent in the lobsters before and after fasting. 



The average weight of my lobsters was 167.3 grams, 

 of which 112.7 grams was water and 35.2 and 19.5 grams 

 was organic and mineral matter respectively. It may 

 be observed further that the 35.2 grams of organic mate- 

 rial are made up as follows: 0.27 gram of glycogen, 1.6 

 grams of fat, 17.3 grams of protein and 8.6 grams of 

 what is commonly designated as "extractive." The re- 

 maining 7.4 grams, or a little over one-fifth of the entire 

 organic matter, is probably chitin, the chief constituent 

 of the shell. 



The same lobsters, at the end of the fast, weighed on 

 an average 162.6 grams. Of this 127.8 grams was water, 

 17.5 grams organic and 17.3 grams mineral matter. It 

 is thus quite evident that one-half of the total organic 

 matter has been lost, having been used up by the lobster 

 in maintaining its existence while no other nourishment 

 was available. It is also interesting to note that the 

 organic material of the starved lobster contained no gly- 

 cogen, only 0.1 gram of fat, 7.8 grams of protein and 2.6 

 grams of "extractives." There is thus 7 grams left over 

 which probably represents the chitin. This quantity is 

 very nearly the same which we found in the lobsters 

 before they were subjected to the fast and we must con- 

 clude therefore that the shell has not been affected by 

 the fast. 



But the most significant fact disclosed by this study 

 is the actual' increase in the quantity of water from 112.7 

 to 127.8 grams. This absorption of water will help to 

 elucidate the circumstance that in spite of the loss sus- 

 tained by the organic portion of the body, the total weight 

 of the lobsters remains almost stationary. Bearing this 

 in mind, we may attempt to compute what the loss was 

 at the end of fifty-six days of fasting. The loss observed 

 in the change of body weight was only 2.73 per cent. 

 Let us suppose, however, that no imbibition of water had 

 taken place. With the knowledge gained from the study 



