IV. On the continuity of the protoplasm Ihrough the walls of vegetable cells. 75 
a precipitation of Jodine actually occurs. Under this treatment tlireads pre¬ 
sent much the same appearanee as.with Picric Hoffmann’s blue. Frequently 
the threads are not of an uniform size, but are thicker near the middle lamella, 
than near the free surface, but I am disposed to think that this is due to the 
greater swelling of that portion of the wall which adjoins the general cell- 
cavity. The pores or channels traversing the pit-membrane are extremely 
fine, and my attempts to inject a coloured liquid into small pieces of the 
endosperm which, bv means of an india rubber cork, were connected wilh a 
niercury manoineter, and exposed to a very considerable pressure, met with 
no success. Altliough I employed an alcoholie solution of Aniline Blue in 
Order to avoid swelling up the wall and thus closing the channels I could 
with the endosperms of Latania and Calamus, obtain no injection whatever 
of any of the delicate pores. 
As far as I was able to observe, there appeared to be no conneetion 
between the tissue of the embryo, and that of the general endosperm. ln 
germinating seeds e. g. those of Kentia, and Phytelephas, the gradual break- 
ing down of the tissue under the action of the ferment, which is probably 
derived from the cells of the encroaching foot or feeder can be followed 
with ease. While the uninjured cells give with Jodine and Chlor. Zinc. Jod. 
the usual yellow colour of the dry seeds, the cells whose walls are under- 
going degeneration, assume the ordinary cellulose blue, most probably in 
consequence of increased hydration. Moreover the changes are propagated 
from cell to cell through the medium of the delicate channels which become 
widened out and finally break down altogether. This occurs with regard to 
the channels traversing the general walls, and to those of the pit-closing- 
membrane also. 
In spite of almost conclusive appearances pointing to the fact that the 
threads eonsist of protoplasm, I feit that some olher definite proof was 
Wanted to show that such was really the case. The staining with Jodine 
cannot be taken as a proof, since besides its multifarious staining properties, 
it demonstrated that all the threads, no matter how altered from their ori¬ 
ginal protoplasmic characler, were equally coloured. The staining elfects 
of Picric IIoffmann’s blue rnay 1 think be taken as quite conclusive for as 
1 pointed out, this reagent fails to colour even protoplasm wlieu much altered. 
In consequence of these considerations I had recourse to the solution of 
Molybdic acid in Sulphuric acid: the staining of which I think further de- 
Dionstrates bevond doubt that in living cells these threads consist of prolo- 
plasm. 
Observalions on Plasmolysis. 
In order to see whether a study of living cells would aftord any evi- 
dence, confirmatory or otherwise, of that close relalion existing between 
Ihe protoplasm and cell-wall, which mv results had demonstrated, I com- 
