6g 
Physiology of the Genus Cuscuta. 
dition so far as I could see, for its whole length, and still 
growing, had attained the surprising length of one metre ! 
This experiment shows not only that close turns are unneces- 
sary to the healthy nourishment and perfect development of 
a branch, but also that the nourishment secured by the 
haustoria of one part can be transported over great distances 
to those parts which are not fed by haustoria of their own. 
In this latter respect it makes little or no difference whether 
a horizontal or an erect branch be used ; for a branch allowed 
to twine on a long vertical glass rod, from which it can of 
course draw no nourishment though it may make close turns 
about it and begin the formation of haustoria (which soon 
abort, however), will attain a very considerable length at the 
same time that its healthy appearance is preserved. 
To show whether or not close turns are necessary to the 
formation of haustoria, the following experiment was under- 
taken. A branch of C. glomerata , in suitable condition to 
wind closely and to form haustoria if conditions favoured, was 
enclosed between the upper faces of two leaflets of a Phaseolus 
still attached to the petiole, whose lower end dipped into 
a bottle of water. The leaflets were kept so closely applied 
against the Cuscuta between two plates of glass of convenient 
size (e. g. 8 cm. long and 4 cm. broad) that it could make 
no curves except in the plane parallel with the surface of the 
leaves and glass. The glass plates were held firmly together 
by a stout paper band around each end. In order to prevent 
their crushing the leaflets and the Cusctita which were pressed 
between them, a strip of glass, two millimetres thick, was 
placed between them at each end. In this way a constant 
contact, accompanied by considerable but not dangerous 
pressure, was maintained for three days. That the branch 
was perfectly healthy was shown by its continuing to grow in 
quite normal fashion. At the end of three days the apparatus 
was taken apart, and it was found that the parasite had made 
no curves, even in the plane parallel with the glass plates, but 
that it had formed haustoria which had entered the leaf-tissue. 
It is, therefore, plain that close windings are not of them- 
