no ANDREWS. 



organisms can be effected to an enormous degree by mere 

 accretion of passive, non-living material, without the actual 

 living stuff being increased at all, for there is a very wide 

 rano-e to the thinness of alveolar films in each structural series. 

 The amount of true living material, as we know it even, is 

 probably very small in any organism. In the young organism, 

 notably in the developing Qgg, the network substance is often 

 markedly thicker than it is in later stages. In the minnow's 

 egg and in the starfish egg this was beautifully shown. While 

 this may not be a rule it is true of many cases. Again, one 

 adult organism may be larger than another and still hold actu- 

 ally much less of the living substance. 



From the physical form of the substance, again, arises 

 infinite opportunity for contractile service of an organized sort. 

 Of physical necessity, the very contact between two vesicles 

 produces planes and lines of continuous and direct field for 

 organized contractility, — nay almost compels it, if the irrita- 

 ble and contractile nature of the lamellar substance be taken 

 into account. 



For receiving and transmitting physically all physical impacts, 

 as well as for appropriating or reacting to, chemical contacts, 

 it would be difficult to conceive of any combination more per- 

 fect than that afforded by the multiplied and extended lamellar 

 membranes of widely variable viscosity and tenuity and curva- 

 ture which the facts have seemed to express as the form of the 

 living, irritable, contractile, sentient, substance. 



The Living Substance; as Such; and as Organism. 



As indicated in areal differentiation, the problems confront- 

 ing us in organization of the foam elements in their specific 

 relation to each other, are but those with which we must deal 

 in understanding the origin of physiological organs or areas, 

 not excepting those of the highest organisms. 



[loi] Conversely, it is even more true that the problems 

 confronting us in the most complex and stable organs of the 

 higher animals are identical with the problems found in the 

 living substance as such, to its smallest visible subdivisions. 

 Nor does it end here, for there is indubitable evidence of 



