66 ASCLEPIADEJ.£. 
- transverse bands or forming merely opaque dots in both cases 
of irregular outline. In next stage the membrane is scarcely 
demonstrable, bursting under the slightest pressure, it is now 
filled with the granular matter, which is not however 
grouped but continuous. 
In a flower-bud 2 lines long the mass has assumed its ma- 
ture form, the outer membrane is cellular, and the granular 
matter divided into masses, corresponding to the cells, the 
inner membrane now appears to exist. 
No other change takes place except in induration, and the 
more complete development of the inner membrane. 
The best mode of accounting for this formation is to as- 
sume, that the original mass, forms directly the grains of 
pollen and that these never lose their original connection; 
or we may look upon the mass as consisting of a single 
original cell, which subsequently becomes indefinitely di- 
vided. To this view, the only objection is the persistence of 
the original cells, but this point is not yet sufficiently de- 
monstrated. - 
CYNANCHUM. 
Cynanchum inconspicuum, Gr. Pl. CCCCI. 
Volubilis puberulum, foliis oblongo-ovatis acuminatis, basi 
profunde cordatis auriculis convergeutibus supra velutino- 
lucidis subtus albidis. 
Racemis umbelliformibus inter petiolaribus, pedunculo 
commune petioli subzquante, pedicellisque pubescentibus 
excedente, calycibus puberulis. Corolla patente-reflexa, laci- 
niis oblongo-lanceolatis, intus lutescentibus extus albidis, 
glabris. 
Ciliz inter-petiolares nulle glandulz ? aggregatia ad basin 
folii cujusque. 
Sorona stam. corolla 1 brevior, 10-fida, laciniis petalis 
oppositis minoribus erectis emarginatis intus carina sim- 
