VI TJie Web of Life 105 



been discovered by Professor Bonnier, who finds that in 

 Euphrasia, Bartsia, and Rhinanthus (though not in Melam- 

 pyrum and some others), respiration predominates over 

 assimilation (see chap, ix.), the oxygen which is Hberated 

 in assimilation being completely masked by the absorption 

 of oxygen in respiration — the very reverse of that gaseous 

 interchange characteristic of the daily life of ordinary green 

 plants. 



The Toothwort. — One of the strangest British plants 

 is the toothwort {Lathrcea sqitanim'ia)^ which has been 

 already mentioned at chap. ii. p. 35. It lives an almost 

 completely underground life upon the roots of poplars, 

 hazels, and other trees, hidden by a growth of ivy, or by 

 a heap of mouldering leaves. No young botanist will ever 

 forget his first finding of the strange pale plant, nor can an 

 old one ever lose his feeling of wonder as he digs down 

 from the thick drooping spike, with its faded lilac-tinged 

 flowers, to the still stranger underground stem, close-set with 

 thick sharp-edged white teeth, more like a witch's necklace of 

 human incisors than a leafy shoot. The plant, though never 

 abundant, has a wide distribution in Europe and Asia. When 

 we bare the thin roots which spring from the underground 

 stem, we see that they are clasped by small adhesive discs 

 to the roots of the tree at whose base the plant grows. 

 From these adhesive discs, which in another European 

 species (^LathrcEa clandestiiid) are about the size of split 

 peas, suckers penetrate the tree-roots, from which without 

 doubt the toothwort steals not only its salts and water, but 

 the abundant starch reserves which help to swell its 

 crowded leaves. Nor does the odd story of life end here ; 

 for each tooth-leaf has a strange recess, no mere hollow 

 of decay, but a normal cavity, narrow of entrance, gland- 

 lined, difficult of interpretation save as an insect trap, 

 as which it is commonly regarded, carrying back our 



