( 770 ) 
tween fome tendons of the upper of thefe raufcles, and the tranrvcrfc 
otitoi the abdamfffy from whence he makes an ingenious fuppofition 
of a trigaftrick^mufcle U \l yNtvt (in each fide) only one,ni3dc up of 
thofe two o( tht diaphragm and that of the abdomen^ one of whofe ten- 
dons is fixed to xhtvertehra of the loyns,aod the other in the linea alba : 
From which connexion of mufcles, in that fuppofition, he aHigns the 
reafon of the dilatation, and contraftion of thcrW^Arin Refpiration. 
The probability of this notion heconfirm%from the cxpanfion of the 
tranfverfe mufcles over the faccuUmembranacei of Birds, which he de- 
fcribcs minutely, and renders a reafon of their refpiration, alcribing 
nevcrthelefs the motion of thofe membranes not only to the raufcUs 
of the belly ,but much to their proper carneous fibres. 
This done,he confiders the chief office of the Diaphragm, v/^. Re- 
fpiration which he defines to be, A paffive motion of the lungs^ 
whereby, upon the dilatation, or contraftion and ftraitning, of the 
thorax, they admit and expel the air, for the cooling the bloud , and 
perpetuating its motion. And takes notice of two diltindions, one of 
Galen, who makes Refpiration to be threefold, i.gentUy from the bare 
motion of the Diaphragm *, 2,ftronger ^hom the concurrence of the in* 
tercoftai mufcles ; iJofty, wherewithal the mufcles of the thorax ^vc 
concerned: Another ©f the Honourable Mr,^<?7/^5who makes but two^ 
branches of hisdiftindion, one moderate from the Diaphragm, ano* 
ther quicker from the intercoflal mufcles. Then, againft Helmont^FaU 
eoburgitu^ Cartefinsy Sic. he afferts that the lungs have fome nvotion of 
their own, from the carneous fibres of the trachxa'r aflSrming, that 
though the femicircular cartilages of it are faid, by the Leariied 2>iV- 
werbrock,^ to be continued by membrancs-,yet that thofe reputed mem- 
branes confift of carneous fibres, and that they ar-e tranfver/ly carried 
from one fide of the cartilage to another : Withal he fuppofes, that 
the fabrick of thefe cartilages is the fame within the lungs, and that 
they have thefe continued either by carneous fibrous ,^ or fome that are 
analogous to carneous ; upon the conftridion of which cartilages 
(the motion of the breaft concurring,) the air, according to him, is 
expelled, and room made for the admiiHon of the bloud from the heart, 
which upon their dilatation^, aad the readraiffionof air, is again ex- 
truded. Then, refuming his difquifition about the motion of the 
Diaphragm, having confidered what others fay GOncerning itsafccnt 
and defcentjhe concludes,that,when uponinfpiration *tis comprefTed 
into the abdomen, tht thorax israifed^but in expiration being propelled 
upwardsjt drawsthe breaft, the breaft prefles the included air,this the 
furfaceof the lungs, whereby tbe air contained in the veficula is exr 
preffed into the branches of the trach^oeai and at laft by them driven. 
forth. 
Next, he endeavours to prove, that the motion of aU the Hamors 
as well as Solid parts, is due to motive fibres .-Where firft he ranks all 
the vcflds in the body (which contain the humorsj under two beads. 
