M. Miiller on the Formation of Starch. 76 



sarily become hollow. It appears however as if the external la- 

 mina of the periphery of the cytoblast is always composed of a 

 harder but still not homogeneous structure. I have often ob- 

 served, that when there was only one cytoblast present in the 

 primary cell, it was encircled by the cytoblastema in which it 

 could be moved like a loose nucleus by rolling the cell to and fro. 



This formation and expansion of the cytoblasts occurs in the 

 primary cell in the greatest variety as regards number and size. 

 I have often been able to count seven cytoblasts of the smallest 

 and largest sizes in a single primary cell. 



If a cell contains a single cytoblast only, this is usually oval, 

 and as well as its cell-membrane preserves that form during its 

 expansion ; but if it contains several, the form is dependent upon 

 their number and arrangement. This form in the nucleus of 

 Chara is somewhat triangular and compressed, especially in the 

 larger cytoblasts. In the smaller ones it is generally very angu- 

 lar. The position of the cytoblasts in the parent cell itself varies 

 considerably. They either lie in'contact, if there dre two, or one 

 lies at right angles to the other {i. e. if the form is oval ; for when 

 simple globules they must necessarily lie in contact) . Hence they 

 are either situated close together or at a distance. If however the 

 primary cytoblast has expanded considerably, so that it almost fills 

 up the cell, it frequently happens that the other cytoblasts widen 

 the membrane of the parent cell still more, according to their 

 own extent. Hence the parent cell acquires numerous projections 

 which always contain their own cytoblasts. Frequently two large 

 cytoblasts exist in one cell and dilate it in two opposite direc- 

 tions. Thus the cell-membrane becomes somewhat contracted in 

 the middle ; and thus the forms of the cytoblasts in the parent 

 cell become changed in various ways, that of the mother-cells 

 being also altered. It can readily be comprehended from the 

 hollowness of the cytoblast, that within the cytoblasts which have 

 become converted into starch, a new deposit of the cytoblastema 

 in the form of starch may occur. It has appeared to me, that 

 in Chara this deposition constantly occurs in the form of minute 

 granules, but this requires to be confirmed by further observa- 

 tions. I have remarked in my paper on the history of the deve- 

 lopment of Chara that the cytoblasts thus converted into starch 

 subsequently become fissured. 



It has also been lately observed by SchafFner in a paper on the 

 growth of cells, that the cytoblasts become hollowed. He noticed 

 it in Chara and in NitellcB [Nitella flexilis), — as it appears to me in 

 the internodial cells between every two cells, — where, as we know, 

 the starch is deposited in considerable masses for the future for- 

 mation of new cells. But if he supposes that new cells with 



