ERRORS EXPOSED 8l 



that he has seen such things, and has even shown them 

 to others, as occurring on branches of viburnum, brionia 

 and on twigs of the plant called horse-tail in Tuscany; 

 but I do not doubt that there was some ocular illusion in 

 the matter, and I do not hesitate to freely record my 

 doubt, knowing Father Kircher to be a sincere lover of 

 truth, who has spared himself neither mental nor bodily 

 fatigue in its eager pursuit. Thus I, having the same 

 object, write my opinion freely, being mindful of the 

 poet's words: 



" If to the truth I prove a timid friend, 

 I fear lest I at last my days may end 

 Among those men who will on History's page 

 Be censured, for they were behind their age." 



And this fear, together with my love of truth, impels me 

 to confess frankly that even I, in days gone by, when 

 blinded by inexperience, have believed in things that I am 

 ashamed to remember now. Really, I must have seen 

 double when I wrote in my " Observations on Vipers " 

 that the heart of the snake has two auricles, and two cavi- 

 ties or ventricles, because a viper's heart has, in fact, 

 only a single auricle and a single cavity; though it is 

 true that the single auricle, when swelled, divides itself 

 into two trunks, as it were, and has internally a fine 

 membrane that almost divides it into two cells ; and it was 

 in exploring these two divisions with the probe that I 

 hit upon the error of the two ventricles, one of which is 

 really there, but the other was carelessly made with the 

 probe. 



I had become so interested in the curious animals, 

 part animate and part woody, described by Father 

 Kircher, and was so desirous of finding some, that I 



