EGG-LAYING IN AMPHITRITE. 



257 



TABLE III. 

 To SHOW THE SPECIFIC GRAVITY OF CCELOMIC CORPUSCLES. 



The coelomic contents were removed after the worm was about through deposit- 

 ing eggs. 



the specific gravity of the ccelomic corpuscles varies between wide 

 limits. However, more than four fifths of them have a density 

 greater than 1.090 and less than 1.123. Contrary to what my 

 previous observations had led me to expect the corpuscles have 

 a density greater than the mature eggs. All corpuscles are 

 heavier and all eggs lighter than a density of 1.085. After stand- 

 ing in sea-water for some time the corpuscles appear to increase 

 in density as shown by test 46, and by other tests not given. 

 Furthermore, the smaller and what appear to be the younger 

 corpuscles have a density less than the older ones. Under 

 these circumstances an examination with the microscope after 

 centrifuging was of course necessary to distinguish between the 

 corpuscles. The significance of these results will be explained 

 later. 



In the course of my experiments the ccelomic corpuscles of 

 both males and females were examined. While not suspected at 

 the time, upon looking over my notes the rather curious fact came 

 to light that the mean density of the female corpuscles is slightly 

 greater than that of male corpuscles. I do not wish to emphasize 

 this fact, for perhaps the number of individuals examined was 

 not sufficient on which to base conclusions. Nor yet do I see 

 whether the significance of these results pertains to nutrition 



