14 Messrs. Brown and Escombe. On the Depletion of the 



which have been degermed in the dry state are, in the 

 first place, steeped in a saturated aqueous solution of chloroform 

 for twenty-four hours. After having freed fche endosperms from 

 adherent moisture, they are warmed gently for a few hours in a flask 

 connected with a water-pump, and are then steeped for a further 

 period of twenty-four hours in I'unning water, every trace of chloro- 

 form being thus removed. The endosperms are then floated in the 

 usual manner on a mica-raft, alongside other degermed endosperms 

 which have been merely steeped in water for forty-eight hours. The 

 two sets of endosperms are thus under exactly similar conditions as 

 regards their liability to attack by micro-organisms, and if the 

 described " sub-aleuronic " changes of the endosperm are due solely 

 to the direct or indirect influence of extraneous organisms the same 

 results ought to be given by the two series, whereas, if the vitality of 

 any portions of the endosperm is a determining factor, evidence of 

 this ought to be forthcoming, since one set of endosperms has been 

 under conditions which would completely arrest the vital functions 

 of any of their component cells.* 



When such an experiment is performed we find very considerable 

 differences between the two sets of endosperms at all stages. Whilst 

 the series merely steeped in water go through the ordinary cycle 

 previously described in detail, the series made up of the chloroformed 

 endosperms show no internal changes for a considerable period of 

 time. In the latter case the " aleurone-layer," which so speedily 

 separates under ordinary conditions, retains its unbroken continuity 

 with the subjacent amyliferous cells, which in their turn preserve 

 their cell-walls and cell-contents intact. Until the growth of micro- 

 organisms has progressed to a very considerable extent the endosperm- 

 contents of the chloroformed grains show no megascopic or micro- 

 scopic change, except in the direction of a more hyaline appearance 

 of the contents of the starch -cells, a change which is apparently the 

 first stage of the "gluten-formation," to which reference was made in 

 an earlier part of the paper. There is neither cytohydrolysis nor 

 amylohydrolysis apparent in the tissues until the micro-organisms 

 which have attached themselves in a zoogloea state to the outside of 

 the " depleted layer" have attained to a very luxuriant growth, and 

 even then the tissue-changes differ in some important particulars 

 from those produced in a "living" endosperm. It is in fact possible, 



* In our earlier experiments it was assumed that a treatment with chloroform- 

 water, sufficient to destroy the vitality of the embryo, would also be sufficient to 

 kill the aleurone-cells. This, however, is not the case, the embryo being much 

 more sensitive to the chloroform than the peripheral cells of the endosperm. We 

 have satisfied ourselves, however, that a twenty-lour hours' steeping of the dry 

 endosperms in chloroform-water at a temperature not less than 15 C. will perma- 

 nently destroy the functionating power of all the cells of the grain. 



