10 



dark reddish lirown, which prol)ably arises from the diti'usion of the dark coloring matter 

 produced. by the spirit. 



The Contractile Cord. 



As above stated, the Polypide is without auy sort of attachment to the cell, in which 

 it lies quite free. But it is attached by means of a long and thin lleshy cord to the axial 

 cord which runs through the creeping part of the Polyzoarium or stem. The attachment does 

 not take place immediately at the bottom of the free cell, but at the bottom of the corre- 

 sponding chamber of the creeping stem, close to the transversal septum which divides the 

 chamber from the next preceding (fig. 10 & 11). This cord, issuing from the body of the 

 Polypide (tig. 3. 5. 10 &c. h) is of very considerable length; as, when the Polypide is expan- 

 ded, it extends not only through the whole length of the cell, but also through the corre- 

 sponding chamber of the stem. The cord is however very thin, filiform, when fully extended 5 

 or G times less than the caliber of the cell, and 4 times thinner than the stomach. It is of 

 cylindrical form, and lies quite free without being attached at any point to the wall of the 

 cell ; but it is nearer to the one side (the ventral) than to the other. Along all one (the 

 dorsal) side it is covered with the same sort of small dark violet spots of coloring matter as 

 the anterior part of the body, the tentacular arms &c., but is otherwise quite colorless and 

 transparent, and is of a soft tieshy consistency. It shews on closer inspection (see fig. 7) 

 in a part of its substance, an extremely fine fibrous structure of fine parallel longitudinal 

 lines and less sharply marked transverse lines; but in the dorsal part these fibres are 

 entirely wanting; and the structure of this part seems to be cellular, and its edge appears 

 somewhat irregularly wavy. With regard to its attachment to the Polypide, this does not 

 take place at the bottom of the stomach, but rather high up on the ventral side where it 

 seems to go over into the thin skin which encloses the digestive apparatus. Its ventral fibrous 

 part may still be traced (see fig. 15) to a considerable distance forward, in the form of a 

 rather wide clear skin-border which gradually disappears in front of the Cardia. In this 

 skin-border, the fine longitudinal fibres may still be distinctly observed diverging like radii; 

 but I was not able to trace their covu-se further. The posterior end, which as beforesaid is 

 attached to the Axial cord at the bottom of the chamber in the stem which corresponds to 

 the cell, is (tig. 6) somwhat enlarged; and all through of a very distinctly marked cellular 

 structure, without any evident fibre. In spirit specimens, the contractile cord* shews itself 

 often irregularly thickened in particular places, and is also thus represented in Allman's figures; 

 but this appears to be only a result of the action of the spirit. In living exemplars I have 

 always found it, whether fully extended or contracted, of a cylindrical form. When the Po- 

 lypide. as is frequently the case, is very strongly retracted, not only to the bottom of the 

 free cell, but also partly in the corresponding chamber of the stem, the contractile cord is 

 always spirally convolved, so that the coils are closer or looser, accordingly as the retrac- 

 tion is stronger or weaker (see fig. 10). Also when, after severing the contractile cord 



