1846.] Linnean Society. 295j 



arranged a number of minute granules ; in others the appearances 

 are more advanced, the granules gradually hecoming larger and the 

 nucleated cell becoming obliterated. From the disturbance that 

 takes place in the position of the granules after detachment from the 

 nucleated cell, it is difficult to determine by what part they were 

 adherent to it ; but Mr. Quekett believes that this adherence takes 

 place at the end at which the point or hilum is observed. Subse- 

 quent to this period the grains of starch enlarge, become laminated, 

 and are multiplied in the manner already pointed out by various 

 observers. 



Such are the results of Mr. Quekett's observations on Exogenous 

 plants ; in Endogenous plants he states that the same process does 

 not appear to be in all cases pursued, inasmuch as while the rhizoma 

 of Iris germanica affords a favourable example for the exhibition of 

 the process as above described, the young stem of Lilhan bulbiferum 

 offers the following differences. Sections taken from the base of a 

 young stem within the bulb have their cells full of starch-grains ; at 

 the height of an inch from the base of the stem, the cells are filled 

 with fluid only, and each cell contains a cytoblast with its contents 

 presenting a milky hue. Carrying on the sections from above down- 

 wards within these limits, the cells are first found to become more 

 transparent and to contain granules with well-defined outlines ; lower 

 down they exhibit minute granules mixed with the fluid of the cell, 

 leaving the cytoblast transparent, empty and angular ; while at the 

 base the granules have arrived at their perfect condition and the 

 cytoblast is no longer visible. Thus it appears, Mr. Quekett states, 

 that there are two modes of formation of starch connected with the 

 cytoblast ; in the one case the cytoblast becomes a nucleated cell 

 and the grains originate on its exterior ; in the other it does not be- 

 come a nucleated cell, but gives origin to the grains in its interior. 



As regards the origin of chlorophylle, Mr. Quekett states that in 

 the plants which he has examined the same mode of development ap- 

 pears to obtain as described in the formation of starch, viz. the gra- 

 nules originating from a nucleated cell, and instances the cuticle of 

 the very young frond of Scolopendrium vulgare, L., as an example ; 

 but he adds that the first origin of chlorophylle is so niixed up with 

 the formation of the cell, that it is impossible to arrive by dissection 

 at the commencement of the process. 



