The Vegetative Anatomy of Molinia caerulea. 61 
neighbourhood of the vascular bundles. In the angles between the 
cells exceedingly small intersticial spaces occur, and layering can 
occasionally be detected in the wall sections. These walls are 
pierced by numerous pits (Fig. 6, P ), which open gradually into the 
cell cavities, forming funnel shaped entrances. Special tests by 
Gardiner’s method demonstrated the fact of intercellular proto¬ 
plasmic connection through these pits and the pit membranes. On 
this account the basal internodes provide splendid examples of 
continuity of protoplasm, and they have the advantages of being 
compact, abundant, and capable of being kept a long time without 
pickling. Tests with iodine solution, sulphuric acid, and double 
indicated in some of the pits, as at P. x 500. 
staining with safranin and haematoxylin (Delafield’s) showed the 
walls to consist of cellulose. In addition to these thickened walls 
the cavities of the cells are packed with granules. Tested with 
iodine the majority of these showed a clear starch reaction, but 
many remained suspiciously irresponsive to this test; they showed 
a decided light brown colour which suggested that some of the 
grains might be proteins, and further tests with Millon’s reagent 
proved this to be the case. In these swollen basal internodes we 
have therefore both starch and protein grains; no attempt was 
made to decide their proportions but the two kinds of grain 
are estimated to be present in the ratio three of starch to one of 
protein. This is the only part of the plant in which protein 
granules have been observed : they appear to be absent from the 
food storage in rhizome and roots. 
