TRANSACTIONS OF THE SECTIONS. 
109 
On the Vascular System of the Lower Annulosa. 
By T. H. Huxlky, F.H.S. 
Under the term Lower Annulosa the author included the Annelida, the l.chino- 
innata, the Trematoda, the Turbellaria and the Rolifera,—in all <>t which there 
t peculiar system of vessels, which have hitherto been universally regarded as 
’ "^-vascular system. Without cun i.li-iin tin ■ i 
^ ?«tion to be fully demonstrated, the author said, that he had to olTVr very 
l * nn f reasons for regarding the prevalent notion SB 1 vaacular 
the higher Annulusa and of tin- MoUtMC® if In all CS8M anon 01 I® - 
part of the common cavity of the body. The iluid which it contains is a 
•tpucnlated fluid ; the propulsive organ, if any special heart exist, is a ContfMS 
, comiceted by valvular apertures with that common cavity. Now, although 
■jlght be incorrect to say that the vascular of the lower Annelida is inva- 
'? distinguished by characters the opposite nf these, still there can be no question 
^ , as a general rule, such is the case; and this circumstance is alone sufficient to 
pave doubts as to the homology of the two systems. Hut these doubts are 
FnrJiUu 1 i 1nG d' w ^ ei1 we take into consideration certain facts, which the author 
atqjj.j “? la 7 hefore the Section. In tin Rotifer* tl ere is a system of vessels, 
"^rviliran a contraetile vesicle, opening externally, from which canals, containing 
*tt C • * ,a5S lnto bot, V. In certain Distomata, such as Arpidogaater 
t 6 * s a system of vessels of essentially similar character; but the 
^hUr th ° 3e ^ atera * trunks which coine oflf directly from the contractile 
tidily dC nt r resu,ar rhythmical contractions. The smaller branches arc all 
tfcvetorynr ’ inotbcr Distomatu the lateral trunks appear to be converted into 
Girdle* bn? 1 j 8 ?* 8 ? re of minute granules ; they remain eminently con- 
^ nwvnf (torn eir connexion with the system of smaller ramified vessels ceases to 
'*» system - ^*Van Bcucden ami others have shown, they still form 
somoitmn the :i: o no ,0 »ger to be found in the smaller ramified vessels, 
■Wtin the mi CS . Van . 1 . C( * altogether; at others, being discoverable only here and 
'■i fascul ar S J t ultimate terminations of these vessels. In certain Ncmntoidea 
a couple of lateral contractile vessels, altogether 
’^is no douhtrt CGn ? mUnica tiugi by a small aperture, with the exterior. Now, 
* ^ratorv an 1 V D nI1 t V cse caSl ' 9 * tllfi "vascular system" is physiologically 
'Waonts the L, P?™ a P s * urinary system; while the common cavity of the body 
f^ioorhyuehus n ’ Va8Ca ^ ar 8 >' 8tc ™ of the Mollusca and Articulata. However, 
f "fiatoij or d:J )08BCSsrs 11 vascular system of the same nature ns that of a 
r A 8 '. n S; thus f t0n ! at0U5 worm, but presenting no cilia, and having no external 
‘.bribed, a n ,i a closed vascular system, homologous with those previously 
/!* a very ( . a „ v tt0ri ' 1 o lmm them only in the fact of its closure. Hut from hence 
author st t i transition to the vascular system of the Annelida; 
r ational reasons , L ’°uviction, based not only upon these, but upon many 
’3' ln fact, nniv it « eSe 80 *Cfcllod blood-vessels and those of the Echinodermata, 
. .'^niof th' c n ];. Ile fina ' term of a series, of which the so-called water-vascular 
1 .'° really nothin ct ? nat,t . utC9 the ccirumnnctfrocnt. If, however, these vessels 
r i '" a j r «a, \yjjjj .8 to “0 with the proper blood-vascular system of the higher 
the ami, S - Vstem o{ organ* are they homologous t In answer to this 
which tut* e ^. b * 8 belief, that they correspond with the tracheae of 
95 in the lar v ? s ‘ m 'l ar * extensive, ramified distribution, and, in some 
,c '* the LibcTlnlicirt*, constitute as completely closed a system 
1 ,c »«el a . 
^ «< p, 
A..,. nUarS <«j- 
Insects am enabtid to ad/irrr to Smooth Perpendi- 
th r ,v amh Qr to k Ur f accs ' Tty Thomas Inman, M.D ., Liverpool. 
by wliiol^ , S / J . rvc y.°^ the whole subject, and pointed out that there were 
Kr^Wfmrvf Wus effected:—1. by hooks, which were used when 
* Cr J 0,r ' hairs exc*m nCR *’ * u lllL> grasses; 2. by suckers, which were perfectly 
' r hich * w hichwas^ U ™ ar 6’ na l fringe to keep the dust out; 3. by an adhesive 
'vere attach , s P reat ^ over an immense number of microscopic hairs, each of 
e to a large llap, and had a distended terminal development. 
