755 



or to a leaf, for I have seen it send its suckers into the leaves of Tri- 

 ticum repens and Plantago lanceolata, as well as those of the clover. 

 If we tear a small piece of the Cuscuta from off the stem of the clover 

 to which it has attached itself, we shall observe some elliptical open- 

 ings through which the teeth or processes [spongioles] of the Cuscuta 

 have penetrated the structure of the ]:)lant, as in fig. 1, c. If we make 

 an exceedingly thin transverse section of the clover (fig. 2), with the 

 dodder {h) uj^on it, and place it under the microscope, we shall then 

 observe the dodder sending wedge-shaped processes (c in figs. 2, 3, 

 and 4) into the stem of the clover ; these processes sometimes pene- 

 trate through the layer of woody fibre [d) to the medullary sheath (e), 

 at other times they can only be traced into the woody fibre, and very 

 often they only enter the cellular tissue. If we examine the long, 

 unattached portions of the stem of the Cuscuta, we may see some of 

 the wedge-shaped processes which have not penetrated any plant ; 

 these consist of a number of oblong cells, arranged in the wedge form, 

 their long axis being placed at right angles to that of the dodder, and 

 uncovered by cuticle ; they are therefore admirably adapted both to 

 penetrate and to absorb nourishment from the plants they attack. 



I think it probable that the Cuscuta is chiefly nourished by the de- 

 scending or elaborated sap, having met with many specimens of clo- 

 ver which were more withered below than above ; if such be the case, 

 the tight embrace of the dodder would act like a ligature, and thus, 

 by retarding the flow of the descending sap, enable the dodder to ob- 

 tain a greater supply of nourishment. 



I believe there is little doubt that the clover from which I obtained 

 my specimens was raised from foreign seed, therefore there is every 

 probability that the Cuscuta was imported : it is most probably the 

 plant alluded to by Mr. Babington in his ' Manual,' as the var. ft. 

 Trifolii of Cuscuta Ej^ithymum. Daniel Wheeler. 



Reigate, September 22, 1843. 



[Mr. Wlieeler's interesting paper was accompanied by recent specimens of the Cus- 

 cuta ; tliese are identical with others previously received from Mr. G. S. Gibson, of 

 Saffron Walden, who last year favoured us with a notice of the appearance of this de- 

 structive parasite in that neighbourhood, (Phytol. 466). Mr. Gibson has since obli- 

 gingly forwarded recent specimens : the note which accompanied them will be found 

 among our Varieties. During the past summer a Cuscuta, with a very slender, white 

 stem, made its appearance on young plants of a Cytisus, in the propagating-house of 

 a Nurseryman and Florist, at St. John's Wood : the species could not be ascer- 

 tained, as the parasite did not flower, but perished after destroying the Cytisus. The 

 following account of the habits and economy of these singular plants, we quote from 

 a provincial paper, — Ed.l 



3t2 



