CONFIRMATION OF BONNET'S EXPERIMENTS. 69 



any naturalist ; because if Bonnet is not to be trusted, 

 on a point so easy of verification, when his statements 

 are so j^recise, and his observations so numerous and 

 minute, no one can be trusted. Fortunately, however, 

 Bonnet is rigorously correct. I have verified his 

 observations under the impulse of Dr Williams's denial; 

 and at the very moment of writing this, I have two 

 Naids in separate vessels, who have reproduced their 

 heads and probosces under the follomng circumstances. 

 The two worms were first cut in half, the fragments 

 which bore the heads were thrown away, and those 

 which bore the tails were placed in vessels, with 

 nothing but water and a little mud, in which, as I had 

 scrupulously ascertained, no worm or other visible 

 animal was concealed. In a few days the complete 

 heads were formed ; the heads were examined daily 

 during their formation. When the animals were quite 

 perfect I once more cut them in two, threw away the 

 head-fragments, and replaced the tail-fragments in their 

 vessels. A second time the heads were formed. A 

 third time the experiment was repeated ; and the worms 

 are now lively, after their fourth section, so that before 

 this passage is printed, I have little doubt they will pre- 

 sent the fourth reproduction of head and proboscis.* 



Amateurs are not fond of worms ; nor, until they 

 have seen Serpulce, Sabellce, and Terehellce^ expanding 

 and waving their beautiful tentacles in the water, can 

 they understand why we should take so much trouble to 



* One died a few days afterwards, but the other made itself a new 

 head as before ; it died, however, after a fifth division. 



