METABOLIC GRADIENT IN ANNELIDS 



11 



were then collected in a funnel of filter-paper, dried on filter- 

 paper, and weighed. The weights of such sets of pieces varied 

 from 100 to 200 mgm. in various experiments. The sets of pieces 

 from the three levels were of course tested simultaneously in 

 each experiment and were handled in the same way throughout. 

 There was some movement among the pieces, particularly at 

 the beginning of the experiments. As far as could be ascertained 

 the amount of movement did not differ in pieces of different level. 



TABLE 1 



Showing the rate of oxygen consumption of pieces from different levels of 

 Lumbriculus inconstans, the pieces taken as illustrated in figure 2 

 and tested simultaneously. Temperatures ± 1 



4- Experimental results. Thirteen experiments were performed, 

 the final results of which are presented in table 1 . The results 

 are calculated in terms of cubic centimeters of oxygen consumed 

 by one gram in twenty-four hours. 



In all of the experiments except no. 12, the anterior pieces 

 consume more oxygen per unit weight per unit time than the 

 middle pieces. The reversal of this result in experiment 12 may 

 reasonably be regarded as due to some error in the course of the 

 experiment, probably a mixing of the sample bottles. In all of 



