Researches in the Theory and Calculus of Operations. 331 



neous outside forces in the production of organs of equili- 

 bration and movement. The first encounter of spherical 

 development with the external fluid medium gives rise to 

 the formation of membrane, skin, cutis, ectoderm, serving 

 as the limit of the individual in space. This membrane is a 

 consolidated force, acting without and within ; in the outer 

 direction, producing shells, scales, cuticle, hairs, feathers, 

 etc. in response to changes of external temperature ; while 

 the interiorly directed action forms directly a living mem- 

 brane or endoderm, which multiplies itself in various adap- 

 tations to the traversing electro-chemical forces encountered. 



To create a living body, the three states of matter, liquid, 

 gaseous, and solid, must come in requisition. A portion of 

 solid suspended in fluid must be supplied as food, to be 

 deposited in that particular form which constitutes the 

 living body in question ; and this deposition arises from 

 encounter of the liquid with the gaseous molecules in the 

 course of circulation. In the very lowest forms of life, this 

 meeting of liquid and gaseous elements happens directly 

 through the surface skin ; while in the high* forms there 

 is a mouth and stomach for the introduction and digestion 

 of the fluid and solid elements, and gills or lungs for the 

 transmission of their gaseous complements. The chyliferous 

 vessels originate from the cylindric pressure of the little 

 capillary streams of the fluid as they spurt through the 

 intestinal membranous pores, and meet the reaction of the 

 surrounding substance in their course. As circumferential 

 gatherings necessarily tend to a centre, the lacteals reach 

 the reservoir termed a heart, which, as itjcannot hold more 

 than its full, is compelled by the stimulus of distension to 

 contract by pulsation, and thus send its contents in circum- 

 ferential directions, supplying everywhere the material for 

 decomposition, renovation and expulsion; and thus is the 

 circulatory system established (Draper). 



