262 Ethel McLennan: 



properties was displayed by different parts of the same hvphae, the 

 coloured portions being interrupted bv colourless, in a very irregu- 

 lar manner. In order to ascertain whether these unstained seg- 

 ments contained protoplasm or were devoid of contents, and thus 

 remained unaltered by the stain, sections were submitted to a 

 second stain following upon gentian violet. Congo red was chosen, 

 as it stains the cell Avails, and also the protoplasm The result wag- 

 that the former uncoloured sections were stained with the red, and 

 displayed dense contents just as is the case with the coloured seg- 

 ments The difference in the staining capacity is probal)ly due to 

 the presence of ferments in certain parts of the hyphal network 

 wherever the ferment is pre.sent in any quancity, then will the 

 "blue" stain be evident. Colour is lent to this idea by the fact 

 that the aleurone layer shows the same staining reactions as the 

 hyphal layer. Ihe majority of the cells do not react to the violet 

 stain, but certain of them stand out markedly from the rest, for 

 they stain densely and form very striking portions of the section. 

 The number of such coloured cells varies in each individual grain. 

 In addition, the scutellum repeats the above phenomenon. In this 

 case, tlie "blue" cells are generally restricted to the epithelial 

 layer of this tissue. 



Brown and Morris (11) liave shown that in Uordtiim rulgare 

 the secretion of diastase is located in tlie aljsorptive epithelium, and 

 in a later paper Brown and Escombe (12) that in addition, the 

 aleurone layer is capable of bringing about marked changes in the 

 endosperm when this is separated from its embryo, and placed 

 under favourable conditions. 



Ihe distribution of tlie active ferment-secreting cells tlierefore, 

 agrees with the staining reactions described above, and supports 

 the view that the coloured segments of the hyphae contain either an 

 enzyme or its fore-runner, and this conjecture is further strength- 

 ened by the later embryological work. 



When examining a sample of English rye grass from Ireland, a 

 specimen was occasionally found showing hyphae (which for the 

 most part stained with gentian violet) invading the starchy endo- 

 sperm. Freeman records a similar distribution for grains of 

 Loliimi temulenfiini from Ghent. A careful examination of the 

 aleurone layer of such a grain showed that the hyphae were also 

 running riot here. Instead of the usual inter-cellular course, many 

 hyphae could be made out actually passing into the cells, and in 

 many cases a single hypha could be traced entering and leaving 



