74 EVENING S AT THE MICEOSCOPE. 



and thick tube that issues from it close behind the point 

 where the gullet enters. This rectal tube passes up- 

 wards parallel to the gullet, and terminates bj an orifice 

 outside and behind the base of the tentacles. All these 

 viscera are beautifully distinct and easily identified, 

 owing to the perfect transparency of the walls of the 

 cell, t]ie simplicity of the parts, and their density and 

 dark yellow colour. All of them are manifestly gran- 

 ular in texture, except the slender corrugated tube 

 which connects the stomach with the globose intestine : 

 this is thin and membranous, and is doubtless, if I may 

 judge from analogy, capable of wide expansion for the 

 passage of the food-pellet. 



The sudden contraction of the polypide into its cell 

 upon disturbance or alarm, and its slow and gradual 

 emergence again, afiord excellent opportunities for 

 studying the forms, proportions, and relative positions 

 of the internal organs. In contraction, the globular 

 intestine remains nearly where it was, but the stomach 

 slides down into the cell behind it, as far as the flexible 

 duct will allow, and the thick gullet bows out in front, 

 showing more clearly the separation between it and the 

 rectum, and the insertion of both into the stomach. This 

 retraction is, in part, effected by a pair of longitudinal 

 muscular bands, which are inserted at the back of the 

 bottom part of the cell, and into the skin of the neck 

 below the tentacles. The contraction of these bands 

 draws in the integument, like the drawing of a stocking 

 within itself, and forces down the viscera into the cavity 

 of the cell, which is probably filled with the vital juices. 



Besides the hind bands, there is one, or a pair of 

 eimilar muscular bands attached on each side of the 

 front part of tlie base of the cell, and inserted similarly 



