16 



GENEEAL PEOPEETIES OF LIVING MATTEE. 



and animal; in the former case, one individual gives rise to a new 

 one ; in the latter, two individuals (male and female) are required 

 to produce a third. It is known, furthermore, that the simplest 

 form of propagation is division, when one individual, after having 

 increased in size, splits into two organisms of smaller size. A 

 variety of this process is the " gemmation " : e. </., a small bud, 

 growing from the surface of the mother-body, becomes gradually 

 pedunculated, and at length separates by breaking of the pedicle, 

 'and forms a new individual. Another variety is the " endogenous 

 formation/' in which a lump originates and grows within the 

 mother-body, and is freed afterward through bursting or active 

 perforation of the mother. Essentially all these processes are the 



FIG. 1. DIAGRAM OF GENERATION. 



The series A represents simple division. The body at first shows a slight impression on the 

 periphery of the nucleus, a / the impression becomes deeper on the nucleus and visible on the 

 body, b ; the nucleus has separated into two nuclei, and the two halves of the body are connected 

 by a thin pedicle, c ; two new individuals have been formed by breaking of the pedicle, d. 



The series B represents the generation by gemmation or exogenous formation. The body 

 projects a solid, homogeneous bud of living matter, a ; the bud is attached to the mother- 

 body by a broad pedicle, b , the bud, by taking into its interior some liquid from without 

 became vacuohul, and is attached to the mother-body by a very thin pedicle, c ; the pedicle 

 has broken, and two new individuals are formed, the original bud having assumed the struct- 

 ure of the mother-body, d. 



The series C represents the yencration by endogenous formation. The body exhibits by the 

 side of. the nucleus a larger lump of living matter, growing from a small granule, a ; the lump 

 lias grown larger and become attached to the wall of the mother-body by a pedicle, at the 

 same time around the lump a space has formed, closed by a flat layer of living matter, b ; the 

 lump lias become enlarged and supplied with vacuoles, c / the lump, now of the structure 

 of the mother-body, has escaped through a perforation of the wall of the mother, d. 



