198 



AGE, GROWTH, AND DEATH 



earthworm, and even among vertebrates ; for he it 

 was that proved that if the head of an earthworm be 

 cut off, the worm will form a new head, with a new 

 brain and a new mouth. 1 He first discovered that 

 if you cut off the tail or the leg of a salamander, a 

 new tail, or a new leg, as the case may be, would 

 grow out. He also made similar experiments on the 



FIG. 66. VIGNETTE FROM TREMBLEY'S CLASSIC MEMOIR, representing Trembley 

 making his experiments on regeneration in fresh-water polyps. 



regeneration of the tail in tadpoles. He it was, 

 moreover, who discovered that this power of replacing 

 the lost part is greater in the young greater in the 

 earlier stage than in the later. These examples may 



1 Lazaro Spallanzani, Prodrome di un opera da imprinter si sopra le repro- 

 duzione animali, 8vo, Modena, pp. 102, 1768. (French translation by de la 

 Sabionne, Geneva, 1768. English translation, An Essay on Animal Repro- 

 auttions, 8vo, London, 1769, pp. 86. The " Prodrome " has been repub- 

 lished in volume four of Spallanzani's Opere Scelte.) 



