No. 460:] STUDIES ON PLANT CELL.—V. . 221 
recent short paper by Michniewicz (:04) describes clearly the 
plasmodesmen in Lupinus, especially in their relation to masses 
of intercellular protoplasm which are discussed at the end of 
this portion of the section. 
It is not clear whether all protoplasmic connections may be 
considered in the same class, as Strasburger would have us 
believe, or whether there may not be some confusion between 
the broader cell connections which are especially conspicuous in 
the thallophytes and certain tissues (sieve-tubes, laticiferous 
vessels), and the delicate protoplasmic fibrils (plasmodesmen) so 
general throughout all tissues of higher plants. As is well 
known, the cells in actively growing regions of the red algze are 
connected by broad strands of protoplasm that are obviously 
left by the cleavage furrow which constricts the protoplasm of 
daughter cells but does not entirely separate them. These open- 
ings may become partially blocked in older portions of the plant 
by the deposition of material so that the connections are finally 
fibrillar but they frequently remain open for long periods, par- 
ticularly in regions where the nutritive processes are active as 
during the development of cystocarps. At this time new 
fusions may be developed between neighboring cells (auxiliary 
cells) so that they become connected in an elaborate network 
around the cells or filaments (sporophytic) that develop the car- 
pospores (Fig. 16,d). The Phaeophycez also furnish frequent 
illustrations of connecting fibrils especially in the Fucales and 
Laminariales where the cells of internal filaments are sometimes 
connected by conspicuous strands. Certain elongated filaments 
which traverse the central region of the larger brown algae show 
a complicated group of fibrils that strikingly resembles the pro- 
toplasmic connections piercing the sieve-plates of higher plants. 
Broad protoplasmic connections are conspicuous between the 
cells of some of the filamentous Cyanophycez (Stigonema, 
Tolypothrix) and in the Chlorophycez have been reported for 
some species of Cladophora (Kohl, :02; Fig. 16, e) and for 
Chaetopeltis, one of the Mycoidee. They do not seem to be 
present in the Conjugales as was at first reported by Kohl 
('91) whose cells show a great degree of physiological inde- 
pendence. In Volvox, studied by Meyer (96), each cell of the 
