220 THE AMERICAN NATURALIST. (VoL. XXXIX. 
reminding one of the central spindle of a mitotic figure (Fig. 
16, c). In general the two types of protoplasmic connections are 
not found together in the same cell or tissue. 
A new point of view was introduced into the discussion by 
the very important paper of Strasburger, in 1901. He consid- 
ered the protoplasmic connections as sufficiently clearly differ- 
entiated structures to rank as organs of the cell and proposed 
for them the name plasmodesmen. Strasburger in agreement 
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clamp connections in Pleurotus (a, after ak Fee: 6 and c, Kohl, :00; d, Davis 
'96 b; e, Kohl, :02; /, Thaxter, '96 ; & Meyer, :02). ; 
with Kienitz-Gerloff opposed the view that the plasmodesmen 
were in any way derived from or related to the spindle fibers 
associated with the formation of cell plates. He believed them 
to be developments of the outer plasma membrane as he like- 
wise considers the cilia in certain zoöspores (see account of 
zoöspore and sperm in Section III, Amer. Nat. vol. 38, pp. 571, 
576, 1904). Strasburger also holds that pores are formed in the 
cell walls by the fermative activities around plasmodesmen. A 
