108 HOFMEISTER, ON 



for a considerable extent with those of the indentation of 

 the bud. The cells which have amalgamated expand con- 

 siderably in length, and to some extent in breadth. When 

 a shoot is formed in each of the two lateral indenta- 

 tions the bud becomes developed into a wide band, on one 

 side of which may be seen the spot at which the bud was 

 attached to the cell which bore it, and which spot is con- 

 spicuous from its brown colour, and by the arrangement 

 of the cells by which it is surrounded. This is the case 

 in Marchantia polymorplia (PL XV, fig. 9). In Lunularia 

 vulgaris, on the other hand, it is a rule almost without ex- 

 ception that a shoot is developed only on one side of 

 the bud, the shoot on the other side becoming abortive. 

 Here the bud in its further growth, assumes the form of 

 a disc drawn out in breadth, and having an indentation 

 on one side. On the other side it sends out a long 

 band, constricted at the fore edge, and on a third side 

 the primary place of attachment is still visible (PI. XV, 

 fig. 20). 



On both sides of the new shoot, and in the angles 

 which it forms with the prominent portions of the lateral 

 margin of the bud, two new cellular masses are formed 

 which are capable of development — in the first place a 

 median, and then two lateral shoots. The shoot com- 

 posed of the three amalgamated shoots unites by its lateral 

 margins with those portions of the next oldest shoot 

 which adjoin it on the right hand and on the left, and it 

 soon makes its appearance out of the indentation, in the 

 form of a flat mass of cellular tissue, having two notches 

 at the fore edge, and becoming wider in front. 



A second form of growth, in which the shoots make 

 their appearance in irregular positions, occurs occasionally 

 in Lunularia and Marchantia, and more frequently in 

 Targionia, Rebouillia, and Pegatella. A process of cell- 

 multiplication commences in individual cells (usually near 

 the median line) of the under side of perfect shoots, by 

 means of which slender, delicate shoots are produced, which 

 soon throw out rootlets, and which, by the decay of their 

 posterior parts, separate from the mother-plant and be- 

 come independent individuals. They exhibit exactly the 



