334 THE POPULAR SCIENCE MONTHLY. 



that state of the eye persists, and when the animal dies, or is sacrificed, 

 it is seen that this eyeball is smaller than its fellow. 



If, now, such an animal were allowed to breed witli another 

 whether operated upon in the same manner or not it would be seen 

 that young which are born, apparently perfectly healthy, present a few 

 days after birth all the phenomena observed in their changed parent 

 or parents. They have the same smaller eyes, but on both sides ; the 

 same ear thickened and enlarged, etc. The only phenomena which 

 they do not show are those which have been transient, the increased 

 heat and the increased sensation which depended upon the increased 

 amount of blood present, etc. 



Those young can be made to breed in-and-in for several genera- 

 tions I have watched them for five generations and always the same 

 characteristics will be discovered in the young. 



If, now, an examination is made of the parent, the first one, it will 

 be seen that the nerve which had been sectioned, or its ganglion 

 which had been extirpated, is not regenerated ; while, if an autopsy 

 is made of one of the offspring of any of the subsequent generations, 

 it is seen that they all possess the nerve and the ganglion intact. The 

 acutest or most minute microscopic examinations do not discover any 

 difierence between their structure and those of other animals of the 

 same family and species. 



If a puncture be made into that portion of the upper part of the 

 spinal cord which anatomists call the restiform body, in Guinea-pigs, 

 it will be seen that the animal presents at once an increased vascular- 

 ity of the ear on the corresponding side ; the ear becomes gorged with 

 blood, chiefly toward the periphery: sometimes in a very short time, 

 indeed, that portion of the ear falls off, destroyed by dry gangrene. 

 I have the record of a case in which the ear was thus partially de- 

 stroyed in less than nine hours. The eye on the same side becomes 

 larger and protrudes ; it protrudes first, and becomes larger in the 

 course of time. 



If a pair of Guinea-pigs thus operated upon be allowed to breed, 

 and even if only one parent is thus diseased, the other being healthy, 

 when young are born, these young always present the phenomena 

 observed in the parents; but the phenomena just described only 

 come shortly after their birth. It is seen that their eyeballs increase 

 in size and protrude from their sockets, their ears after a few days be- 

 come diseased, just like those of the parents, the subjects of experi- 

 mentation, and drop off, eaten by dry gangrene. 



When the parent or parents are sacrificed, and their restiform 

 bodies are examined microscopically, nothing is detected but a cicatrix 

 in the envelopes of the spinal cord, which appear a little thickened at 

 that point, but the nervous tissue itself does not differ apparently from 

 surrounding elements of the same nature and structure. If an exam- 

 ination is also made of one of the young, nothing at all is discovered. 



