296 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



treatment continued until the straw-colour of the spirit 

 remains permanent. It may then be assumed that all 

 the sublimate has been removed. The worms may then 

 be transferred to fresh 90 per cent, spirit, and kept therein 

 until required for sectioning. 



The segments required for sectioning are dehydrated 

 by passing through absolute alcohol (three changes), and 

 are then placed in either xylol or cedar-wood oil. The 

 writer has found the latter very satisfactory, provided that 

 care be taken to ensure the thorough removal of the oil 

 when imbedding in paraffin wax. That is, the specimen 

 is transferred from cedar-wood oil to the first vessel of 

 wax and afterwards to a second and third, before finally 

 imbedding. The time required in the bath, of course, 

 depends on the size of the tissue, but for a piece say half 

 an inch long by an eighth of an inch in diameter from 

 2 to 3 hours would be sufficient, except in the case of the 

 anterior end where a little longer time is desirable. Wax 

 with a melting point of 56° to 58° C. is best for Arenicola. 



The best results are obtained by staining the sections 

 on the slide by means of iron-alum-hsematoxylin. If 

 this be too long a process the specimen may be stained in 

 bulk (before cutting into sections) with borax carmine, or 

 Mayer's acid-haemalum. Some of the sections, especially 

 those in which it is desired to show gland cells (e.g., in the 

 stomach*) may, with advantage, be stained with Mayer's 

 acid hsenialuni or with Grenacher's or Delafield's 

 hcematoxylin. 



Transverse sections are useful for the study of the 

 general anatomy, alimentary canal, nephridia, &c. ; 

 sagittal sections of the anterior end are helpful in the 



* The histology of the alimentary canal of starved specimens 

 should be checked by the study of sections of small pieces removed 

 from a worm immediately after taking it from the sand. 



