38 



THE STARCH CELL. 



sinks in that place where the nucleus is situated. On the surface minute fissures 

 appear, two of which almost regularly diverge towards the thicker end of the grain. 

 The grain continues to be depressed inwards until a cavity is formed, which is sur- 

 rounded by an elevated edge. In proportion as the grain swells up, this ridge increases 

 in circumference, and decreases in breadth ; that is, continues to get flatter, until fissures, 

 mostly of a star-like form, appear in the hitherto little altered thicker part of the grain. 

 The process is not very rapidly developed, and it is very difficult for the eye to follow 

 it. Suddenly something is torn off, the grain is extended lengthways, and in the next 

 moment a wrinkled skin of a rounded, generally oval shape, lies on the glass." Fur- 

 ther examination shows that they are collapsed bodies, consisting of an extremely fine, 

 but strong and elastic, membrane. 



Mr. Busk obtained a different impression from his experiment. He considered that 

 the line upon the surface were simply plaits or foldings, and that the whole process 

 consisted of unfolding these plaits, and, by distending the cell, to render the cell- 

 wall perfectly plain and free from any markings. In Fig. 79 A, we have the starch 

 of the horse-chestnut in its unaltered state, and at B is i epresented a stage of the 

 unfolding which results from the use of the sulphuric acid. Fig. 79 c, D, and E, 

 represent other views of this process, showing that the cell becomes gradually larger, 

 until it reaches the great size figured at F. The fringe around the figures c, D, 

 and E he regards as plaits in the process of being unfolded. 



Figs. 80 a b, have been copied from Schlieden's work, and represent the starch 

 from the cormus or roots of the Arum maculatum, 

 of our hedges, and of the Colchicum autumnale, in 

 which the star-like centre is presumed by Mr. 

 Busk to indicate the central folding of the mem- 

 brane referred to by him. 



On a review of the whole evidence now offered, 

 we may infer that the starch granule consists of 

 a cell- wall, contracted and plaited when dry, and 

 smooth and distended when heated with mois- 

 ture, and also of contents in insufficient quan- 

 tity to fill it, and thereby leaving a central 

 cavity. 



On this principle, it is difficult to conceive 

 that the plaits can retain the same characters 

 in the same plants under all atmospheric condi- 

 tions ; and it is proper that we should state that 

 Dr. Allman of Dublin has, during the present 

 year, published an article in the Quarterly Fig. SO.-Starch cells copied from 



Journal of Microscopic Science, in which, by a fhnflp ft . Schlieden. 



.-L, - ,, ' * i those of the Colchicum autumnale. 



the same processes as those above indicated, he *, those of the Arum maculatum, both 



has come to totally opposite conclusions. In his foldTn^o^cavfr 611 * degrees the central 

 opinion the statement of Fritzsche is correct c, the centra? clvi^y well developed in the 

 viz. , that the starch cell is in fact a series of cells, 8tarch f the Ia18 - 

 placed within each other, as exhibited in Fig. 80 . He sums up his opinions in the 

 following words : 



1st. That the starch granule consists of a series of lamella, in the form of closed 

 hollow cells, included one within the other, the most internal inclosing a minute cavity 



