12 



Winifred E. Brenchley. ''The Development of the 

 Grain of Barley^ Annals of Botany. 1912. 26, 903— 

 928. 



This investigation was carried out on the same Hnes as the 

 earlier work on wheat. The increase in weight of the whole plant 

 which has gone on during the growing period ceases about 15 or 18 

 days before harvest, and a fall in weight sets in through dessication 

 and other changes. This is the critical point at which maturation 

 begins. From now onward there is no further change in the 

 actual amount of nitrogen or phosphoric acid present in the grain, 

 although the percentage amount rises by reason of the loss of 

 moisture and carbohydrate. The ash decreases somewhat, the losses 

 being comparable with those observed by Le Clerc and Brezeale 

 and attributed by them to leaching. These changes are hardly seen 

 in wheat, which has a much shorter ripening period. 



Observations were made on the accumulation of the starch. 

 This was found to be deposited progressively from the chalazal end 

 of the grain up towards the embryo, its first appearance being in the 

 cells in the flanks of the grain. 



Certain nuclear changes were also observed : the nuclei first 

 lose their nucleoli and then gradually get deformed and squeezed out 

 into networks of varying degrees of coarseness. The deformation 

 may be attributed to the pressure of the increasing starch grains ; 

 it seems to progress from both ends of the grain simultaneously 

 towards the middle, and the last cells affected are those of the sub- 

 aleuronic layer of the endosperm. 



Lilian xM. Underwood. "A note on Onion Couch.'' Journal 

 of Agricultural Science. 1912. 4. 



One of the commonest grasses in the hedges and thickets of 

 this country is the Tall Oat Grass (Arrhetiatherum avenaceum, 

 Beauvais) ; it is often found in meadows also. A form of this grass 

 known as "Onion Couch," distinguished by the possession of a chain 

 of swellings or knots at the base of the stems where the nodes swell, 

 is a common weed on arable land, especially on lighter soils. As 

 each knot is capable of giving rise to a new plant, the weed is 

 dangerous and difficult to eradicate. 



Botanists differ as to whether the bulbous form is entitled to 

 specific rank. Bentham and Hooker do not recognise the onion 

 form at all, while Keichenbach distinguishes it as Arrhenatherum 

 nodosum and Lindley as Arrhenatherum bulbo^iim. The question 

 is whether the swelling is a congenital variation of specific value or 

 the outcome of physiological response to the conditions of the habitat. 



To test this point, seeds of the two forms were sown in pots 

 containmg respectively moist and dry soil, sandy soil and clay soil, 

 in shady situations and conditions of checked evaporation. In all 

 cases the plants were similar to the parents : the bulbous form 

 remained bulbous and the other form did not develop swellings. It 

 appears therefore that the habit of forming bulbs is hereditary and 

 does not depend on the conditions of the habitat. 



William A . Davis. " The Estimation of Potassinm, 

 especially in Fertilisers, Soil Extracts and Plant AsJies."' 

 Journal of Agricultural Science. 1912. 5, 52 — 66. 



