1892.] The Tendrils of Passiflora caerulea. 205 
genus Cribraria (in common with the rest of the Hetero- 
dermez), similar in construction to those of Lindbladia except 
that they are permanent and not evanescent under the condi- 
tions above detailed ; second, the similarity of the sporangia 
of atleast one species, Crébraria argillacea, with its practically 
permanent wali, to those of the stipitate and substipitate 
forms of Lindbladia effusa var. simplex. 
It is, therefore, a legitimate inference, that Lindbladia and 
Tubulina, although they closely approach each other, having 
been similarly developed along parallel ordinal and partially 
parallel generic lines, probably arose from independent and 
perhaps widely separated points of origin. 
Philadelphia, Penn. 
The tendrils of Passiflora caerulea. 
D. T. MAC DOUGAL. 
(WITH PLATE XIV.) 
I. Morphology and anatomy. 
The work recorded in this first paper was undertaken for the 
Purpose of determining the factors in the movements of the 
tendrils of the Passiflorzs, more particularly the movements by 
which atendril responds to a stimulus, resumes its original 
Position, Or on continuance of the irritation coils permanently, 
and its Subsequent changes while coiled and serving as a sup- 
Port for the weight of the adjacent part of the plant body. 
maccePting as entirely tenable the view that the other move- 
aus of the tendril are the results of conditions of growth 
ying states of turgescence, they will be are pi 
: i 
the continyi 
dissimj] 
of conductin 
logical ch 
Which thj 
