1(36 THE INDUCTIONS OF BIOLOGY. 



and animals. Continuous multiaxial development is 



that which plants usually display, and need not be illustrated 

 further than by reference to every garden. As cases of it in 

 animals may be named all the compound Hydrozoa and Ac- 

 tinozoa; and such ascidian forms as the Botryllidoe. Of 



multiaxial development that is discontinuous, a familiar 

 instance among plants exists in the common strawberry. 

 This sends out over the neighbouring surface, long slender 

 shoots, bearing at their extremities buds that presently strike 

 roots and become new individuals; and these by and by lose 

 their connexions with the original axis. Other plants there 

 are that produce certain specialized buds called bulbils, which 

 separating themselves and falling to the ground, grow into 

 independent plants. Among animals the fresh-water polype 

 very clearly shows this mode of development: the young 

 polypes, budding out from its surface, severally arrange 

 their parts around distinct axes, and eventually detaching 

 themselves, lead separate lives, and produce other polypes 

 after the same fashion. By some of the lower Annelida, this 

 multiplication of axes from an original axis, is carried on 

 after a diiferent manner: the string of segments sponta- 

 neously divides; and after further growth, division recurs in 

 one or both of the halves. Moreover in the Syllis ramosa, 

 there occurs lateral branching also. 



Grouping together its several modes as above delineated, 

 we see that 



f Unicentral 

 " Central ^ or f Continuous 



Multicentral -{ or 



(^ Discontinuous 



Development is < 



or 



Uniaxial 

 Axial -{ or f Continuous 



1^ Multiaxial ^ or 



1^ Discontinuous 



Any one well acquainted with the facts, may readily 

 raise objections to this arrangement. He may name forms 



