THE LIVING SUBSTANCE. 



145 



with flux of Biitschli's structure and of interalveolar foam. 

 Even in organisms having complex vascular systems, the work 

 of these must be supplemented by just such minor or more 

 primary dissemination processes, in order to reach areas whose 

 continuous stuff has no immediate contact with vascular cur- 

 rents. For much protoplasm in every organism, the continuous 

 substance, as alveolar lamellae and as interalveolar channels, 

 currents, and filose processes, both physically and physiologi- 

 cally carries on this work, — which means to the substance as 

 such just what the grosser vascular systems mean to the 

 organism. 



Every new formation of ectosarc however fleeting extends 

 the parasitism of the substance as such. And every new 

 area producing, or segregating, materials needed for contractile 

 or irritable function of the substance elsewhere, acts as a 

 device to furnish parasitic areas with their specific environ- 

 ment, that is, with their intimate opportunities, or causative 

 conditioning. Besides that physical restraint which the pres- 

 ence of more solid inclusion matter may cause the contractile 

 powers of the substance ; secretions, or chemical processes of 

 primary digestion may also to some extent restrain, inhibit, 

 or intermit these. They may be necessarily alternative or 

 secondary results. The converse may also be true. With 

 regard to Biitschli's structure, ectosarcal areas stand often for 

 secretory habits of more or less pronounced character, for in 

 this structure, as stated before, all sorts of materials are 

 deposited, and an organized number of vesicles having kindred 

 deposits would mean, or indicate, a local habit of the general 

 substance as such. If fluid, such deposits form physical 

 opportunity for organized contractile and irritable function. 

 In other cases these inclusions may serve to inhibit character- 

 istic activities of the substance, and then this will commonly 

 be withdrawn by degrees to more free conditions. In many 

 cases parasitic areas take from the general store, or from 

 special areas, matter which is useless or positively hurtful to 

 the substance, or which is to be transported elsewhere, or held 

 in constraint for coming substance organs. (See Heredity.) 

 Such are many wandering cells of Metazoan systems. These 



