Chap. I. HISTOLOGY OF CORYNE MIRABILIS. 209 



columnar body, the more slender part of which {Figs. 5 and 6, b), being nearest to, 

 and in direct connection with the opening (/) of the cell, corresponds to the neck 

 of the expanded state ; the lateral projections (c), nearer the centre, are the barbels 

 in a non-everted condition ; the thickest portion (/>^) is the same as the tapering 

 base of the thread, and the spindle-shaped figure [b"^) is the hollow through which 

 the whole mass of the thread {d) passes when it is everted. Nearer to the mouth 

 of the cell the opposite walls of the neck {b) meet, and do not leave such a 

 hollow channel as exists further inward. At the end of the cell, opposite to the 

 mouth, the contents appear darker than elsewhere, and crescent-shaped. In profile 

 the horns of this crescent {Fig. 5, d) may be traced along the sides of the cell, 

 toward its mouth. The centre of the concave part is in direct connection with 

 the broader end (i^) of the axial column. By careful focusing within the range 

 of the inner surface of the cell, a veiy faint set of bands are, with much difficulty, 

 brought out, which run obliquely, or, rather, around the outskirts of the cavity, in 

 a spiral direction {Fig. 6). The horns of the crescent, mentioned above, are here 

 («) the thickness of the spiral layer, which winds around the cell towards the 

 mouth (/). Interpreting this spiral \ayev from Avhat we know, positively, of the 

 nature of a similar layer in the lasso-cells of Polyps, we have no hesitation in 

 considering it to be the lasso-thi-ead coiled up in its capsule. 



Professor Clark has lately communicated to me the following observations, which 

 relate to some points of the structure of the lasso-cells, which I had overlooked 

 in my observations upon this subject: 



"On the 19th of March, 1859, whilst studying the cellular structure of the 

 outer wall of Coryne mirabilis, I detected that it was crowded with innumerable 

 elongated lasso-cells (PI. XP. Fig. 15), whicli laid in every possible position. These 

 cells closely resemble those of Polypi; and all are elongated ovate, with the nar- 

 rower end tapering, and slightly bent. The thread projects backwards from the 

 broader end of the cell, where it forms its basal attachment, and trends in a nearly 

 straight line {b) half way to the other end, keeping, at the same time, close to 

 one side of the cell, and then bends upon itself and returns nearly to its base, 

 and then, again recurving (c), passes back along the opposite wall, nearly to the 

 first bend ; and so it goes and returns, forming each time a coil {d e), until five, 

 six, or seven of them are laid down between the two ends of the cell; and the 

 thread terminates at the narrower end. Thus it will be seen that the part which 

 is usually called the base {b) of the thread, does not stand within the coils 

 {c d e), as heretofore observed in Polypi, but is entirely on one side of them, 

 and close against the Avail («). These cells are excessively transparent, and much 

 smaller and much more numerous than the form commonly observed, with the three 

 recurved barbs. This is the first instance in which the relations and point of 



VOL. IV. 27 



