THE CELLULAR TISSUE. 



As, for instance, the Lungs give the blood its color here 

 elements are thrown off and others received. The digestive 

 tube, as already mentioned, performs the initiatory steps 

 in its formation and the organs of excretion are so many 

 purificators in the process. 



But we have blood formed where there is no organ or set 

 of organs to account for it as in the egg. All we see is 

 the germinal membrane, which has the power of assimila- 

 ting the fluids of the egg to itself, and converting them 

 both into blood and organized vessels. 



"This fact," says Professor Muller, "teaches us that we 

 must not expect to discover the process of the formation of 

 the blood and red particles in any special organ of the 

 adult." "Indeed," he continues, "it is very probable that 

 in the adult the chyle is converted into blood under the 

 same general vital conditions which are in action in the 

 incubated egg." From this it would seem that nature has 

 not assigned the formation of the blood solely to any par- 

 ticular part or organ of the body. But, in the language 

 of Dr. Stevens, "when more agents than one are concerned. 

 in the production of certain effects, we ought not to con- 

 sider any one link in the chain as the sole cause, for all 

 the animal functions act in a circle, and are mutually 

 dependent upon each other." 



CHAPTER III. 



THE CELLULAR TISSUE. 



ANALYSIS. 



STRUCTURE, EXTENT, FORM, QUANTITY, CONSISTENCY, CONTINUITY EXTERNAL 

 AND INTERNAL CELLULAR TISSUE RELATIONS, USES, DEVELOPMENT. 



CELLULAR Tissue (called also Areolar and uniting Tissue) 

 consists of filaments of white, soft layers, intermixed and 

 interwoven in different ways, so as to form an arrangement 



