402 Mr. Bowman 07i the Parasitical Connection 



flowering stems of a young plant, carefully cutting and sawing 

 off all the roots of the Ash-tree (under which it grew) that came 

 in contact with the spade, without disturbing the central mass. 

 When the trench was sunk lower than the horizontal roots of the 

 tree, I caused the labourers to undermine the insulated lump on 

 all sides, and to lift it carefully into a large garden basket, in 

 which they carried it into a neighbouring and rather rapid 

 stream : here, by repeated and cautious agitation, I at length 

 washed away all the soil, leaving exposed the roots and fibres 

 of the Ash, and the subterranean stems of the Lathrcea com- 

 pletely matted and entangled together. On separating them, 

 I had the satisfaction to find the parasite with its root, of the 

 size, shape, and habit represented in Fig. 2. This clearly shows 

 its true character, and solves the problem, that though its base 

 is not inserted into the stock, as in Orobanche, but is spindle- 

 shaped and terminates in many forked fibres, it is strictly para- 

 sitical, each fibre being furnished with very minute tubercles, 

 which fix themselves on the roots of the tree to extract their 

 juices. It is only by means of these that the fibres can perform 

 their oflSce of ducts. As these tubercles are also copiously found 

 on the fibres of the subterranean stem, and will be best described 

 with it, I shall for the present defer the detail of them, noticing 

 only two or three of an extraordinary size, which may be 

 seen in Fig. 2.6, on the upper part of the caudex of the root. 

 These are of a much firmer and more woody texture than the 

 smaller ones, and their interior organization is more complex, 

 though they perform the same functions. A magnified longitu- 

 dinal section of one of them is shown in Fig. 4 ; but it will be 

 better understood hereafter. The exterior of the caudex is of a 

 red-brown, and tolerably smooth ; its texture is solid and woody. 

 A cross section of it exhibits very numerous angular cells con- 

 nected by a fibrous network, which forms the solid portion. 



It 



