643] SEROLOGICAL PHENOMENA 



127 



before us we might suppose tliat as long as all tissues 

 are in normal physiological balance no antibody or similar 

 modifying agents are developed. The germ-cells, there- 

 fore, maintain the exact constitution they derived from the 

 zygote from which they descended. But with the occur- 

 rence of injury, undue stimulation or pronounced change 

 in any part of the body, serological changes would prob- 

 ably be produced in the blood-stream and the germ-cells 

 would then be exposed to possible modifying influences. 

 This would be more likely to happen, of course, if the ex- 

 posure continued through a long period of time. If the in- 

 fluence were disintegrative or poisonous as the cytolysins 

 or cytotoxins evidently are, then probably degenerative 

 changes would ensue. Such a hypothesis affords, perhaps, 

 a plausible explanation of such deteriorative evolutionary 

 processes as those seen in the formation of vestigial or- 

 gans. As a concrete illustration, purely hypothetical of 

 course, we may suppose that such a species as the mole 

 in gradually changing to a subterranean existence would 

 meet with frequent injuries to the eyes, and that, as a 

 result of the ensuing inflammatory and suppurative con- 

 ditions, resorptive influences would be set to work which 

 not only affected the proteins of the eye, but also the 

 related proteins of the germ. Once the degenerative proc- 

 ess got to going, it might for a time be based in each new 

 generation upon both the direct chronic irritation to the 

 eye and the parallel changes induced in the germ. Fi- 

 nally, we may suppose that the somatic influence would 

 cease when the eyes liecame of small size and the eyelids 

 remained permanently sealed, but that the conditions 

 induced in the germ would persist. If such atrophied 

 eyes continued to be resorbed more or less in each gen- 

 eration, however, variation toward still further reduction 

 might continue in the germ. Such a progressive degen- 

 eration might possibly be ranked as an instance of re- 

 gressive orthogenesis. 



But what of the progressive aspects of cvohition ! C^an 

 serological reactions l)e invoked liere with any >how of 

 reason! One great difliciilty in .lealing with pn.iiressive 



