No. 450.] STUDIES ON THE PLANT CELL. 



drawing upon food that has been prepared for them 

 stored in special structures (as seeds, spores, bulbs, c" 

 factured in differentiated organs or tissues (leave- 

 bearing tissue, phloem, etc.). 7^he vegetative lu tiv 

 plasm are far more specific than those of geini p 

 tissues have particular and highly developed ;u ti\ itu' 

 ing chiefly with photosynthetic processes, sonu- (ph 

 uting the organized food over the plant IxhIn, somo 

 food in large quantities. Besides these there ar ■ 

 functions performed by highly differentiated tissue s, 

 largely composed of empty cells, as the vasculai tis 

 ing tissues, and the external protective integunu iits. 



It is not our purpose to discuss any of these \ e- 

 ities in detail, but only to distinguish as sharplv as 

 characteristics of germ plasm with its generalized a- 

 the specialized body plasm. These generalized i 

 before stated, are constructive activities which ineai 

 lead to nuclear and cell division. It is probable th; 

 which presents them has regenerative powers th; 

 proper environment might be expected to re])roduce 

 entire organism. Germ plasm is distributed more wi- 

 out the organism than is generally supposed, and 

 specialized tissues still retain the spark of re^ene 

 bilities. The significance of these conditions is 

 appreciated, perhaps because the environmental 

 regeneration are little understood and are exceed- 

 adjust experimentally. There is i)resented here a \- 

 field of botanical investigation, a union of cell stuc 

 more gross anatomical methods of experimental 1 



2. Cell Division. 



Cell division takes place only after periods 

 have led to a multiplication of nuclei and in the t 

 above the thallophytes is very generally a part ol 

 each mitosis. This is because of the structure 

 plate which is essentially an organ of cell dm 

 thallophytes present other methods ot cell divis 

 no es^Decial relation to nuclear activities, and in i ' 



