204 Alfred J. Ewart : 



were removed fr«m the water, and hand sections were cut of the 

 seed-coat. These sections were stained on the slide with chlor- 

 zinc-Iodine, and the stain, after remaining: for one to two 

 minutes, was washed off with glycerine water. Examination of 

 the sections shoAved that in every instance., almost without excep- 

 tion, a structureleS'S cuticle wais observable on the exteaior of the 

 seed coat. The cuticle was clear and well defined, becoming 

 stained bright yellow, while the cell-walls of the subjacent pali- 

 s.ade tissue assumed the characteristic violet or bluish tint of 

 cellulose. The internal contents of thesie cells were, like the 

 cuticle, stained yellow. In nearly all /Cases sections were aJso 

 prepared from the swelled specimens, disclosing the fact that in 

 some no cuticle at all was developed, presumably due to the 

 immature condition of the seeds ; whilst in others the cuticle 

 appeared to be well developed, indicating that the seed had been 

 injured and the cuticle brokeo at some point or points, rendering 

 it peirmeatble at that point or points. 



In every instance the cuticle was easily distinguishable when 

 stained with chlor-zinc-iodine, but Beirgtheil and Day were unable 

 to discern the cuticle in the seeds of Indiciofcra arrtcta when 

 using this reagent, and in urder to render the cuticle visible they 

 employed a solution of Iodine in Phosphoric acid. Following on 

 their method, I made up some of this stain, but though the 

 results were alwaiys satisfactory, in no instance was the differen- 

 liation so complete as when chlor-zinc-iodine was used. This 

 suggested the possibility that the chlor-zinc-iodine solution used 

 by Bergtheil and Day might not be of the correct consistence, 

 and I obtained seeds of Indigofera arrecta in order to test them 

 with my solution. I found that I obtained the same results as 

 when the other seeds were used, so that it was evident thait the 

 ohlor-zinc-Iodine solution used by Bergtheil and Day was at fault. 

 A distinct cuticle was present in the Indigofera arrecta, whilst 

 there was no trace of a cuticle structure in the sections of 

 Indigofera sumatrava, treated with chlor-zinc-iodine solution. 



In some of the seeds examined, notably those of Lahirhea 

 lanreohtfa, the whole of the structureless cuticle did not appear 

 to be spcciallv resistent, ])ut there was a narrow edge on the free 

 side of the cuticle which stained a deeper yellow, and which on 

 treatment with strong sulphuric acid, disintegrated into seg- 



