304 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



INTRODUCTION. 



I. Methods. 



My investigations have been carried out on the living 

 worm by teasing out certain parts of the body, and by 

 means of a large number of series of transverse and 

 longitudinal sections. 



I have found the method of teasing out certain 

 parts of the worm, either in water or salt solution, quite 

 invaluable. By this means all the reproductive organs 

 can be liberated and examined in the living condition, 

 and very pretty staining effects have been obtained by the 

 addition of methylene blue. Certain parts of the 

 nephridia can also be obtained in this way, especially 

 the vesicle referred to later. The vesicle is always 

 removed with portions of the nephridial tubes, but it is 

 difficult to remove all the nephridium because the tubes 

 are much coiled, and the nephrostome lies in the next 

 segment in front as in all other Oligochaeta. 



In preparing specimens for section cutting, various 

 preserving fluids and staining reagents were employed. 

 The killing process is a difficult one, as the contortions of 

 the worm on the addition of any chemicals are very 

 violent. The worm, if left to itself during the process, 

 becomes so bent and shrunken that it is useless for 

 sectioning. It is advisable, therefore, to hold the worm 

 at both ends while it is being immersed in the killing 

 fluid, and thus any serious contraction of the internal 

 organs may be prevented. The great disadvantage of 

 this method is that the brain and anterior part of the 

 nerve cord are usually pressed out of shape, but it is easy 

 to hold a few specimens nearer the middle, while killing 

 them, when the anterior end can be obtained in fairly 

 good condition. 



