THE ROTATORIA. 
$$ 187, 188. 147 
CHAPTERS VI. AND VII. 
CIRCULATORY AND RESPIRATORY SYSTEMS. 
§ 187. 
As no sanguineous system has yet been found with the Rotatoria, it must 
be admitted that all the organs are bathed directly by the nutritive liquid 
which transudes through the intestine.® 
§ 138. 
The vessels observed with the Rotatoria belong probably to the aquiferous 
system, which, from its structure and limited distribution, must be regarded 
as of a respiratory nature. In most species, a straight and riband-like organ 
is seen upon each side of the body, which contains a stiff, tortuous, vasculi- 
form canal. At the anterior extremity of these two lateral bands, their 
canals connect with many short lateral vessels which open into the cavity 
of the body, — their orifices being furnished each with a very active, vibra- 
tile lobule. 
These lateral orifices have the appearance of pyriform, or oval corpus- 
cles, in the interior of which, the vibratile lobule, produces the aspect, when 
its motions are diminished by pressure between plates of glass, of a small, 
flickering flame. 
The number of these organs varies with the species, and also, it would 
appear, even with different individuals of the same species. 
1 The sanguineous vessels which Ehrenberg has 
frequently described and figured, have not ap- 
peared as such to Dujardin (Infusoires, p. 589), 
Rymer Jones (Comp. Anat. p. 125), Doyere 
sAnn. d. Sc. Nat. XVII. 1842, p. 201), and my- 
self, 
The so-called annular vessels encircling the body 
‘of many species at regular and wide distances, and 
which, as he himself avows (Die Infusionsthier- 
chen, p. 415), are not connected by longitudinal 
‘vessels, are undoubtedly only the transverse sulca- 
*[§ 187, note 1.] Dalrymple (Phil. Trans. 
1849, p. 334) has described with Asplanchna 
Brightweliii what he regards as a peculiar cir- 
culatory system. It “consists of a double series 
of transparent filaments (for there is no proof of 
their being tubes or vessels), arranged, from above 
downwards, in curved or semicircular form ; sym- 
metrical when viewed in front. These filaments, 
above and below, are interlaced loop-like ; while 
another fine filament passes in a straight line, like 
‘the chord of an arc, uniting the two looped extrem- 
ties. To this delicate filament are attached tags, 
Usually there 
tions, or muscles. From their extreme tenuity, it 
is difficult to determine the nature of the other fili- 
form organs in the body of the Rotatoria, and which 
Ehrenberg has also referred to the sanguineous 
system. But, equally well might they be taken for 
“ muscular fasciculi, ligaments or nerves.* 
1 Ehrenberg was the first to point out these 
vibratile organs,and designated them as the inter- 
nal gill-like respiratory organs (Abhandil. d. Berl. 
Akad. 1833, p. 183). 
or appendices, whose free extremities are directed 
towards the interior of the animal, and are affected 
by a tremulous, apparently spiral motion, like the 
threads of a screw. This is undoubtedly due to 
cilia arranged round these minute appendices. 
The tags are from eight to twelve, or even twenty, 
in number, varying in different specimens.” He 
thinks these organs fulfil their function by the cil- 
iated tags producing currents in the fluid which 
fills the body of the animal. 
These observations are curious and deserve fur- 
ther attention. — Ep. 
