FISSION— GEMMATION. 4I 



portions, and the parent-creature is resolved into a swarm 

 of off-shoots. 



This multiplication by mere division of the mass pre- 

 supposes that the organism thus reproducing itself pos- 

 sesses no high complexity. The bisection of a beetle 

 or a bird is inconceivable as a means of propagation. 

 Yet Stein's valuable observations on the reproductive 

 process of the Infusoria, make us acquainted with organ- 

 isms standing far above these simple so-called Monera, 

 of which the subdivisions undergo a series of profound 

 metamorphoses, before separating as self-dependent indi- 

 viduals. This transformation, combined with fission, 

 leads to reproduction by gemmation. 



As the fission of these low organisms depends on the 

 attainment of a certain limit of growth conditional on 

 adequate nourishment, the case now more frequently 

 occurs that the individual discharges the superfluity of 

 material obtained at a definite part of the body, and 

 forms a bud or gemmule. We are already acquainted 

 with reproduction by gemmation in the simplest organ- 

 ism, the cell; for all healing and cicatrization in higher 

 beings, even to the re-integration of the mutilated limbs 

 of amphibians, is effected only by the reproduction by 

 fission and gemmation of the elementary morphological 

 constituents. But it lies in the nature of the process of 

 gemmation, that it should extend far higher than fission 

 in the scale of organisms; it is the origination of a new 

 being from one already existing, the latter, meanwhile, 

 preserving its individuality wholly or for the greater 

 part, and yet being able to transfer to the progeny its 

 own characteristics in their full integrity. 



The simplest case of gemmation is where the parent 



