Oct. 1, 1867.] 



HARDWICKE'S SC1E NCE-G OS SIT 



223 



and shrivelled, and entwined together into one mass 

 so intricately that it appeared at first sight impos- 

 sible to separate them by any other means than 

 that adopted by Alexander with the knot of the 

 Phrygian's famous harness ; but although they re- 

 sisted all attempts to flatten or uncoil them, they 

 proved to be sufficiently elastic to bear the amount 



Fig. 221. Tail, x 99. 



Fig. 222. Head. 



of force required to tear them from each other's 

 folds. In colour some were a pale yellow; but the 

 majority were more or less longitudinally streaked 

 with brown, in some cases approaching to black. 

 On placing one of them in water, it speedily 

 began to untwist itself, and to •writhe about 

 in a manner strongly suggestive of returning 

 animation ; but although it is said that Gordius 

 aquaticus will come to life again and swim away, 

 after having been dried up for weeks, I am quite 

 sure that these movements on the part of the 

 many specimens of Mermis examined were merely 

 the result of the relaxation of their stiffened bodies, 

 consequent upon the absorption of the fluid in 

 which they were immersed, the motion entirely 

 ceasing as soon as the last trace of shrivelling had 

 disappeared. The absorption of the water appeared 

 to take place almost entirely through the substance 

 of the skin ; and it is stated that in their natural 

 condition they obtain their nutriment in a similar 

 manner. When thoroughly moistened, their bodies 

 became naturally distended, cylindrical, transparent, 

 and pliable in a remarkable degree, and so elastic 

 that they bore stretching to much beyond their 

 natural length without breaking asunder. On 

 placing them under the microscope, upon moistened 

 slides, I found that the dark colour of most of the 

 specimens was due to the presence of large numbers 

 of clear brown ova, which, in many instances, filled 



the body from within i inch of the head to i inch 

 from the tail, no fewer than 7,200 of them having 

 been counted in the first one taken under examina- 

 tion. In length the worms varied from 3* to 5i 

 inches, and in breadth or diameter from ^ to $fc 

 inch, excepting at the extremities. The tail ended 

 in a somewhat curved and rounded point, and there 

 was no posterior aperture to the intestinal canal. 

 From a distance of about | inch from the head the 

 body gradually tapers down, until it terminates in a 

 slight rounded enlargement, just behind which there 

 is a small, ill-defined, red spot ; the diameter of the 

 head in most cases does not exceed -j^ inch. 

 Whether this worm has any mouth or not appears 

 to have been hitherto a matter of some uncertainty, 

 for in works where its characteristics are given I 

 find it frequently stated, " Mouth none, or very in- 

 distinct ; " and from the examination of nine out of 

 ten mounted specimens, it was impossible to decide 

 the question with any certainty ; but in the tenth I 

 was delighted to find that the structure of the 

 mouth was shown in a remarkably clear and beau- 

 tiful manner ; for although this slide, as a specimen 

 of mounting, is anything but what it ought to be, 

 the head is more perfectly shown than in any former 

 instance. Erom the examination of this, I think it 

 may be determined that the creature is furnished 

 with at least two very minute circular mouths or 

 suckers, one on each side of the head, about 90° 

 apart, or 45° on either side of the terminal extre- 

 mity, from each of which a cone-shaped tube ex- 

 tends towards, and at its base joins, the alimentary 

 canal. There is also some reason for suspecting the 

 existence of one or more additional mouths. The 

 body is filiform and cylindrical, its integument being 

 perfectly transparent, homogeneous, very elastic and 

 tough, and seemingly of a gelatinous nature. It 

 absorbs water with great facility, undergoes no 

 perceptible change from the action of sulphuric 

 acid, but is instantly dyed brown by a solution of 

 iodine. Its effect upon polarized light is very 

 slight, unless iu a state of tension, when it becomes 

 brilliant, and exhibits beautiful graduating colours 

 with selenite. The most noteworthy appearance 

 connected with it is that it is delicately marked 

 with an immense number of striee, which run 

 spirally round it from end to end, preserving their 

 parallelism throughout, their distance apart scarcely 

 exceeding - 



j- inch. These markings are best seen 

 when the worm is freely floating in fluid, and has 

 not been subjected to pressure. (The specimen 

 exhibited under the microscope in the room was 

 placed in a glass cell containing water only, and in 

 which it had been for more than two months with- 

 out undergoing any perceptible change.) Whatever 

 may be the nature of these markings, they seem to 

 indicate the secret of the creature's climbing 

 powers, and to confirm the opinion that it ascends 

 the stems of shrubs by a winding spiral motion. 



