

VEGETATIVE STRUCTURE OF MESOGLOIA. 159 



tube thus formed become granular, and do not stain read- 

 ily, being probably mucilaginous in nature. 



Frequently the interior of the central cylinder has a 

 orowth of hyphue and short club-shaped branches resem- 



om 



The branches in the material that I studied had their 

 origin in the cortical cells immediately surrounding the 

 central row of cells. The branching, as shown by the 

 accompanying figures (2, 7), in each case is from the cells 

 adjoining the central row of cells but not from those cells. 



Eeinke's* account of the method of growth of Chor- 

 daria, including C. divaricata, according to Henckel, has 

 not been verified by any observer since. He claims that 

 the growth is intercalary and extends over the tip of the 

 stem at the basal segments of the paraphyses which stud 

 the tip. However, in point of structure, his figures and 

 account are verified by my sections except that the apex 

 of the central filament does not end in a globular cell 

 as he' shows in his figuresf. Henckel states that the 

 growth proceeds from a single terminal cell which cuts off 

 lateral cells parallel to the axis of the stem. He shows a 

 similarity of growth to that of Dictyosiphon as described 

 by Murbeck. From my own observations, I infer that the 

 growth in length depends upon the lengthening of the 

 central row of cells, which proceeds in a twofold man- 

 ner. One is real growth of the apex of the central row 

 of cells from an apical cell. The other is increase in 

 length of the central cells by stretching. This stretching 

 is at least partially, if not wholly, caused by the growth of 

 the cortical cells which proceeds both upward and down- 

 ward from its point of origin from the lateral cells cut 

 off from the central row of cells. Growth in thickness 

 originates by the cutting off of the cortical cells from cells 



Algenflora der westlichen Ostsee, deutschen Antheils. (Bericht der 

 Kom. zur Untersuch. der Deutschen Meere in Kiel. 17-19 1 : 67. (1889). 



f Luc. cit. 



