ACALEPHiE. 
239 
^oinewliat in the manner of a pocket foot-rule. It is to the 
to mbined effect of contraction and the unfolding of the pieces that 
these lines owe the marvellous changes of length which they 
I®esent,” In Fig. 96 are represented the polypes and fishing-lines 
P. hydrostatiea, with a portion of the disk and two pairs of repro- 
ductive clusters. 
In. this figure it will he observed that each fragment or joint has 
^planted, near the articulation, a secondary fine, which bears the 
Ringing organ. Each of these filaments consists of three parts : a 
Haight stem, muscular, contractile, and hollow, the cavity of which 
c °nununicates with that of the trunk which carries it ; a middle part, 
a B °rt of tube containing, hr a considerable internal cavity, a trans 
l ,f U'ent liquid ; finally, an inflated stinging organ, which terminates 
6 Apparatus. This last is egg-shaped, and consists internally ot a 
Juline substance of cartilaginous consistence, in the interior of which 
find a great cavity, which opens from within, near the base of the 
<l ]*ule ; to the inside of this cavity a second muscular sac is attached 
^ round the opening of the capsule, in such a manner that the 
°P e ning leads directly into the cavity of the sac. This cavity conceals 
^ its interior a long filament usually rolled up in a spiral, as illus- 
; l ' at ed h Fig. 97 ; w here the two urticant capsules of the stinging 
apparatus of Physophora hydrostatiea are represented, one of them 
I* 1 ? a section, magnified by twelve diameters. This spiv ally 
(;r l-up filament consists of a large quantity of very small, hard, 
-Shaped, corpuscular bodies, supported the one against the 
er , and having their points turned inwards. These objects Vogt 
“urticant sabres:” the extremity of the filament consists 
curved mmnanEo lar-mii- of a brownish vellow. verv strong, 
anfi 
"with a double point. M. Vogt had also opportunities of ob 
]® l 'ving the action of these stinging capsules. He has seen them 
j lls I Naturally, and he has also obtained artificially the same result. 
0 £ lle former case the filament issues from the opening left at the base 
U ,^ 1<: ca psule with a sort of explosion. “ The use,” ho says, “ of the 
m 8'lines becomes evident when we see a Physophora in repose 
a Vase large enough for its full development ; then it takes a 
leal position; the lines elongate themselves more and more, by 
the°P^® ° ne ^ one tlie secolldai 'y lilies witl1 still 8 in g ca P sules > an d 
e I^ysophora now resembles a flower posed upon a tuft of roots, 
