GENETICS 



diate demands of the tissues that make up the indi- 

 vidual. In one instance at least, that of the nematode 



worm As cans, 

 according to 

 Boveri, this 

 splitting off or 

 isolation of the 

 germplasm oc- 

 curs as early in 

 thei cleavage of 

 the fertilized 

 egg as the six- 

 teen-cell stage, 

 when fifteen of 

 the cells go to 

 form the soma- 

 toplasm and the 

 sixteenth is set 

 aside as germ- 

 plasm. 



Thus there 

 results a con- 

 tinuous stream 

 of germplasm, 

 receiving con- 

 tributions from 

 other germ- 

 plasmal streams 

 at the time of 



X 



Germplasm \ Somatoplasm 



7 ^ 



FIG. 3. Scheme to illustrate the continuity 

 of the germplasm. Each triangle repre- 

 sents an individual made up of germ- 

 plasm (dotted) and somatoplasm (un- 

 dotted). The beginning of the life cycle 

 of each individual is represented at the 

 apex of the triangle where germplasm and 

 somatoplasm are both present. As the 

 individual develops each of these compo- 

 nent parts increases. In sexual reproduc- 

 tion the germplasms of two individuals 

 unite into a common stream to which the 

 somatoplasm makes no contribution. The 

 continuity of the germplasm is shown by 

 the heavy broken line into which run col- 

 lateral contributions from successive sex- 

 ual reproductions. 



sexual reproduction, as shown diagrammatically in 

 Figure 3, in which individuals are represented by tri- 



