•THEAICP^COPE 



:ated 



Vol. XI. 



TRENTON, N. J., AUGUST, 1891. 



No. 8. 



ORIGIMAL 



C°AnvriicATions 



CELL-DIVISION IN PLANTS. 



PROFESSOR DOUGLAS HOUGHTON CAMPBELL, PH. D. 

 PLATE III. 



AS botanists concern themselves more and more with the bio- 

 logical aspects of the science, the problems connected with 

 the structure and multiplication of the plant-cell are assuming 

 great importance, and it may interest the readers of The Micro- 

 scope to have in brief form some of the results of the later in- 

 vestigations on the subject. 



Strasburger has probably done more than anyone else to ad- 

 vance our knowledge of the plant-cells, and to him we owe very 

 much in regard to the minute structure of the cell, and the pro- 

 cesses of cell-division. 



The complete plant-cell, as is well-known, consists essentially 

 of three parts, viz., cell-wall, protoplasm and nucleus. Besides 

 these, other structures may be present such as the plastids, of 

 which the chloroplasts or chlorophyll-bodies are the most fa- 

 miliar. These plastids are now known to be, when present, es- 

 sential parts of the cell, and are always formed by division of 

 pre-existing bodies of like nature, and never arise from undif- 

 ferentiated protoplasm. 



