206 TRANSACTIONS, NATURAL HISTORY SOCIETY OF GLASGOW. 



windstill chamber, into which the stomata of the under surfaces 

 open, as, e.g.., in Viola atropurpurea.'^ 



Actual dragging down of the stem is found in, e.g., the tubercles 

 of many orchids, which may be buried 6-10 centimetres. It has 

 been recorded for Monkshood, Ranunculus bulbosus, Linn., Lilium 

 Martagon, Primulas, Auricula, and the Carrot. ^ 



Amongst the Rosacete, the node of the strawberry runner is 

 drawn a centimetre deep into the soil. The stolons of Ruhus 

 hifrons, Vest, are also drawn down by the roots, according to 

 Korner yon Marilaun.^ 



The explanation given is, that the root contracts or shortens 

 sometimes as much as a third of its length, so that the plant is 

 drawn down. We were examining some roots of the Raspberry 

 near Aikenhead, and found that the older roots were almost 

 invariably thrown into complicated curves and spirals. They 

 develop chiefly in the loose leaf-mould which is scarcely decom- 

 posed, and they spread almost horizontally to a considerable 

 distance. 



In one case we found what appeared to resemble pretty closely 

 an ordinary tendril. The root had a straight portion and two 

 coils, one on each side. Subsequent examination showed us that 

 such appearances are very common, though not by any means 

 general. With branch tendrils this is due to the revolving of the 

 free parts of the tendril after it has become attached to the 

 support. The result is, that the stem is drawn closer to the 

 branch, and the coiling affords a give-and-take to the wind, 

 which is of some importance. 



Darwin's law, that all the parts or organs of every plant, whilst 

 they continue to grow, are continually circumnutating, gives a 

 very simple explanation of the coils and curves of these Rasp- 

 berry roots. 



Once the root end is fairly fixed in the ground, then the free 

 part of the root that is still growing may behave like a tendril, 

 and throw itself into these curious coils. The result is, that the 

 stem parts are drawn into the ground, and a great mechanical 

 advantage is gained. The specimens handed round show the 

 tendril curvature. 



i Meigen, Engltr's Jahrhuch, Bd. XVII*, 1894; 

 - Kdrneri Natural Histoty of Plants^ 



