G50 THE MARINE ANNELIDES OF THE ORDER SERPULEA, 



The methods of preparation which I have employed are mainly 

 the following : — For dissociation of elements, such as muscular 

 fibres or epithelial cells, I have used immersion in weak alcohol 

 (90% alcohol 1 part, water 2 parts) for two or three days ; 

 followed by picrocarmine and Farrant's solution. For hardening 

 I have found the corrosive sublimate and alcohol method 

 preferable to any other. The most perfect stain for the general 

 histology of the tissues is effected by an absolute alcohol solution 

 of eosin, followed by Kleinenberg's hematoxylin, both dyes 

 being used very dilute and the pi'ocess being extended over four or 

 five days. The chloroform-paraffin method of Giesbrecht (1), 

 though a little tedious, is preferable to any other method of 

 embedding for the present group as for most others, and par- 

 ticulaidy so when employed in conjunction with Caldwell's 

 invaluable ribbon method of cutting sections with the automatic 

 microtome. The series are best fastened to the slide with a 

 weak solution of gum arabic (2), and the paraffin removed with 

 benzol, which should be followed by oil of cloves and Canada 

 balsam dissolved in chloroform. In cases in which sections 

 prepared as above show, on examination before final mounting in 

 balsam, that some part which may be specially required is not 

 adequately stained, the following fluid will be found useful, — 



Saturated solution of hematoxylin in absolute alcohol, 100 c.c. 



Oil of cloves 100 c.c. 



Saturated solution of alum in water, 2 c.c. 



This fluid mixes with the benzol and does not cause solution of 

 the gum arabic ; its action, owing to its clarifying effect on the 

 tissues, can be watched with great ease. It should be removed 

 and replaced by oil of cloves before balsam is added, as, should 

 any of it be allowed to mix with the balsam, a process of slow- 

 staining will still go on after the sections are mounted. 



(1) " Zur Schneide Technik," Zool. Anz., 1881, No. 92. 



(2) J. H. L. Flogel, Zool. Anz. VI., 565. 



