AND INHERITANCE IN PEDIASTRUM. 



425 



under the influence of the stresses and pressures developed in the 

 growing colony. We have noted, however, that the cell form char- 

 acteristic for the species is visible at once as the swarmspores cease 

 moving and is only sharpened and made more definite with the 

 further growth of the cells. On the other hand, it is equally obvious 



Fig. 35. Type diagram from a selected individual, colony No. 55. Re- 

 produced from '16, Fig. ib. 



that abnormalities of form — shortening, elongation, change of direc- 

 tion of the lobes, etc. — as well as the regular blunting of the 

 peripheral lobes of interiorly placed cells are all direct environ- 

 mental epigenetic results dependent on the interrelations of con- 

 tact and pressure between the cells in the forming and growing 

 stages of the colony. 



