ARTIFICIAL MULTIPLICATION OF POLYPS. 105 



is the case in various other zoophytes, it is not abso- 

 lutely excluded from any period of the year. 



It appears from some experiments of Sir John 

 Dalyell, that a greater number of polyps than are 

 allotted by nature to a single individual may be ob- 

 tained, almost at the pleasure of the observer, by 

 making artificial sections or cuttings of the zoophyte, 

 and in this way twenty-two Hydrse have been made 

 to originate from three sections of a single stem : the 

 phenomena attending this process are sufficiently 

 remarkable to make a repetition of the experiment a 

 matter of interest. A luxuriant head having fallen 

 from a specimen, the stem, previously detached from 

 its original site, was divided into three portions, the 

 lowest two inches long, and each of those above it of 

 the length of one inch. Nothing resulted from the 

 highest segment, where growth might have been most 

 expected ; but in ten days a head burst from the lowest, 

 where it might have been least expected, and in four- 

 teen days another sprouted from the top of the middle 

 section; and in this manner the Hydriform polyps 

 may be artificially multiplied by a repetition of a 

 similar mode of proceeding, apparently to an inde- 

 finite extent. 



F 5 



