be tall, yet are its sides but thin: and because again, it should grow not only tall and thriftily, but for avoiding propping up, strongly too; therefore, as its height is over-proportioned to the thinness of its sides, so is its Circumference also; being so far dilated as to parallel a _Quill_ it self. Besides the position of the _Lignous Body_ within the compass of a Ring, we see some shootings thereof often standing beyond the Circumference of the said Ring, making sometimes a triangular, oftner a quadrangular Body of the _Trunk_; to the end, that the Ring being but thin, and not self-sufficient, these, like Splinters to _Bones_, might add strength and stability to it. Next, the security and plenty of the _Sap_. For should the _Lignous Body_, as it doth in the _Root_, its smaller parts, stand Central here also, and so the _Cortical_ wholly surround it: the greater part of the _Sap_ would thus be more immediately expos’d to the Sun and ayr; and being lodg’d in a laxe Body, by them continually be prey’d upon, and as fast as supplied to the _Trunk_, be exhausted. Whereas the _Pith_ standing in the Center, the _Sap_ therein being not only most remote from the Ayr and Sun, but by the _Barque_, and especially the _Wood_, being also surrounded and doubly immur’d, will very securely and copiously be conveyed to all the Collateral parts, and (as shall be said how) the top of the _Trunk_. And the _Sap_ by the amplitude, and great porosity of the _Pith_ being herein more copious, its Fermentation also will be quicker; which we see in all Liquors by standing in a greater quantity together, proceeds more kindly: And being tunn’d up within the _Wood_, is at the same time not only secur’d from loss, but all extream mutations, the Day being thus not too hot, nor the Night too cold for it. And the Fermentation hereof being quicker, its motion also will be stronger, and its distribution more effectual, not only to the dilatation of the _Trunk_, but likewise the shooting out of the Branches. Whence it is, that in the Bodies of Trees, the _Barque_ of it self, though it be sappy, and many Fibres of the _Lignous Body_ mixed with it, yet seldom sendeth forth any; and that in Plants, those with the least _Pith_ (other advantages not supplying this defect) have the fewest or smallest Branches, or other collateral Growths: and that _Corn_, which hath no _Pith_, hath neither any Branches. Lastly, the Advancement of the _Sap_ will hence also be more ready and sufficient. For the understanding where, and how, we suppose that in all _Trunks_ whatsoever there are two parts joyntly hereunto subservient. In some the _Lignous Body_ and the _Cortical_, as in older _Trunks_, the _Pith_ being either excluded or dried: But in most, principally the _Lignous Body_ and _Pith_; as in most Annual Growths of Trees; but especially Plants, where the _Cortical Body_ is usually much and often wholly inserted.