ROOTS OF THESIUM LINOPHYLLUM. 147 
into the very heart of its supporter, often causing very con- 
siderable derangement in its tissues. After the perfection of 
the first tubercle, the root is continued from the side of the 
tubercle, so as to give it the appearance of having been . 
formed laterally, and proceeds at greater or less intervals to 
form more tubercles in the same manner on the same or 
neighbouring roots. On the larger roots of its supporters 
it is not usual to find more than one or two tubercles; and 
these are mostly large: the largest I have seen being about 
the eighth of an inch in diameter; but on the fibrous roots 
of grasses and other small plants they are very small, and 
may be frequently found succeeding each other so quickly as 
to resemble a small string of beads. / 
Like Cuscuta, our species of Thesium appears to be by no 
means particular in the selection of its supporters; and I 
have ascertained its attachment to the roots of the following 
plants, viz.: Anthyllis vulneraria, Thymus Serpyllum, Lotus | 
corniculatus, Daucus Carota, Scabiosa succisa, Carex glauca, 
and some grasses : it is probable that a single plant of Thesium — 
subsists, at the same time, on the roots of the wholé of the oe 
plants above enumerated. - eee 
Through the kindness of Mr. Borrer I have been able * 
examine the specimens published in Reichenbach" s Flo 
Exsiceata; and 1 find the roots of Thesium a À 
x F ebracteatum, Hayne, i rostratum, Koch iyl- 
lum, Lim, to have precisely : the same structure as that of 3 
Owe species. Unfortunately. the roots of the other - 
ecies contained in this collection were too imperfect to 
afford any information ; but from the very close relationship - 
Ment MTM. species, there | is ipie ground to 
