HEREDITY 



49 



A remarkable illustration of inheritance without expres- 

 sion is seen in the case of the alternation of generations 

 (pages 33-35). The inital protoplasm of the sporophyte 

 is all inherited through the fertilized egg from the game- 



FiG. 35. — Vegetative propagation of Haworthia sp. Tlie new plantlet 

 forms on the flower stalk, below the flower-cluster. Ultimately it falls 

 to the ground and takes root, becoming established as an independent 

 plant. 



tophytes, but most of the gametophytic characters do not 

 appear in the sporophyte, nor do the typically sporophytic 

 characters find expression in the gametophy te. ^ (C/. p . 40 .) 



' The chlorophyll, of course, is an exception. But the osmotic strength 

 of the cell-sap is a different expression in gametophyte and sporophyte, 

 otherwise the young sporophyte could not live parasitically upon the 

 gametophyte. 



