ON CIRCULATORY STASIS 281 



encircling cutaneous expansion have been reached or art 

 has stepped in to avert final consequences? Who, more- 

 over, would suppose, on the spur of the moment, that a 

 fully developed hydrocephalus had originated in a simple 

 closure of the central cerebro-spinal lymph exits, and a 

 consequent damming back and accumulation of that fluid, 

 with its far-reaching results on the processes of local 

 ossification, and formative extension of the external 

 cephalic structures? 



And what more evident than the cause of the atrophic 

 effects of arrested blood circulation on the process of 

 nutrition of the tissues to which the affected vessels and 

 arrested circulation lead? 



In every instance of circulatory stasis it will be found 

 that relationship to the heart and blood vessels determines 

 to a large extent the manner of incidence of the arrestment 

 phenomena, thus the proximal and the distal sides of that 

 relationship, while they are attended with different dynamic 

 procedures, yet combine to produce one unbroken system 

 of circulation, beginning at the oral orifice of the body 

 and terminating at its various eliminatory exits ; on its 

 proximal side the circulation being effected by a vis a 

 fronte, and on its distal side by a vis a tergo, each of 

 which is alike the product, directly and indirectly, of 

 cardio-vascular contraction, aided by the other general 

 circulatory agencies operative in organic fluid movements. 

 As we have elsewhere contended, the central and indis- 

 pensable element in this circulation, both in its initiation 

 and maintenance, is the creation of auricula-ventricular 

 vacua, which result, on the distal side of the heart, in 

 sending currents of blood away from it and along the 

 arterial vessels, and on the proximal side in bringing 

 currents of blood into it and along the venous vessels, 

 both of which currents, while sustained by muscular 

 agency, superinduce throughout the whole range of the 

 subsidiary and uniting circulations forward movement of 

 the various fluids within these circulations, nutritive and 

 effete alike, to the end that one continuous forward circu- 

 lation of the entire fluid contents of the body should be 

 maintained without stasis or regurgitation. The alternate 

 contractions and relaxations of the heart in rhythmic 



