404 Mr. Bowman on the Parasitical Connection 



been very imperfectly understood. Its subterranean stem throws 

 out from between the scales many succulent and tender fibres, 

 bearing a profusion of minute tubercles or bulbs, which fix 

 themselves upon the roots of the Ash, Hazel, &c. and extract 

 their juices in the manner shown in Fig. 3. These tubercles are 

 principally formed near the extremities of the fibres ; they are 

 either solitary or in groups of two or three, and bear some 

 external resemblance to small beads, or the knotty excrescences 

 on the roots of some leguminous plants. The connecting fibres 

 are so tender, that it is difficult to get them up without breaking 

 off the tubers, which are left behind upon the root of the stock. 

 The tubers are brown, semiglobular, and succulent, and usually 

 not larger than a small pin head ; so that, even should a few 

 remain on the fibres after being dug up, they might escape 

 observation among the soil that adheres to them. Hence I 

 attribute their having so long escaped the notice of botanists. 

 Neither these tubers nor their fibres are to be found in the very 

 spirited woodcuts of Matthiolus, Parkinson, or Gerarde*. Sir 

 J. E. Smith (English Flora, vol. 3. p. 128.) alludes to the fibrous 

 character of the root ; but though he says he believes it to be 

 parasitical, he does not explain in what way. On first washing 

 the Ash roots, I was astonished to find some of them thickly 

 studded with the tubercles adhering closely to the bark on all 

 sides, and to the fibrous roots of the parasite, in the manner I 

 have represented in Fig. 3. To remove all doubt on this head, 

 I traced these fibres from the tubers to their insertion in the stem 

 between the imbricated scales of the Lathrcea, and, by the aid of 

 the microscope, through its cellular bark to their junction with 

 the ligneous part which ranges round the medulla. It was ne- 



* The figure in Matthiolus is the largest and best of the three ; but the flowers in all 

 are too small, and too thinly scattered on the stem. The cut in Gerarde (edit. 1597) 

 is « copy from Matthiolus, but reversed and on a smaller scale. 



cessary 



