214 PHYSIOLOGY AT THE FABM. 



the molecules and granules may be various albuminous, 

 fatty, pigmentary, or mineral matter. When of still larger 

 size, as in the milk, they are termed globules.* Molecular 

 fluids are fluids in which organisation is proceeding, or the 

 fluids within cells containing the commencement of new 

 germs, or the deposits of secreted or effete matter. Molecular 

 fibres are fibrous arrangements of molecules or organic fluids. 

 Molecular membrane, the chief example of which is the sub- 

 stance of cell-walls, is composed of molecules closely aggre- 

 gated together. Molecular movements are the movements of 

 molecules floating in a fluid, the laws governing which have 

 not yet been clearly ascertained ; these may be vibratile, cir- 

 cular, spiral, serpentine, or wholly irregular. 



" When we know," says Dr Bennett, " that essentially differ- 

 ent fluids, as oil and albumen, when brought into contact, 

 immediately precipitate molecules that assume a globular, 

 fibrinous, or membranous form, and that such a process is 

 facilitated by numerous chemical reagents, acids or alkalies 

 acting on albuminous, fibrinous, or mineral solutions, we 

 readily observe one way in which histological elements may 

 be produced within the body. Such elements, subject to the 

 laws of vitality, may be formative elements (histogenetic), 

 whilst others may be retrograde, and give evidence of vital 

 cessation (histolytic). Hence the first and the last element is, 

 as regards the form, the molecular. Organic formative fluids 

 deposit molecules, which arrange themselves, subject to vital 

 laws, into nuclei, cell-walls, and higher textures. These, once 

 produced, subsequently decay in an inverse order, breaking 

 down into individual fragments, and ultimately into minute 

 molecules. During the whole life of an individual organism, 

 we observe in it a constant series of these formations and dis- 

 integrations, of these histogenetic and histolytic actions/' -f- 



* Bennett, 'Outlines of Physiology,' pp. 14, 15. t Ibid., p. 17. 



