From the Introduction: "Division Chlorophyta, or green algae, presented in this volume, are found to grow in fresh and brackish waters as well as in marine habitats with varying range of nutrient and salinity concentrations. A number of them grow as Benthic and Pelagic plankton. Still there are many species of green algae that are capable of growing in terrestrial and subaerial conditions. Their body organization may vary from unicellular to colonial forms, tubular to filamentous, leafy to siphonaceous and pseudoparenchymatous to heterotrichous type. Most of them having cellulosic cell wall and uninucleate to multinucleate chloroplasts. In the cellular pigment content, chlorophyll is predominant and starch is the reserve food.

In Bangladesh, except for the work of Kundu (1929, 1934-35), Banerjee (1935), De (1939) and Fritsch (1945) no other investigation was carried out on algae, particularly after 1945. The reason for such poor record on algae in Eastern Bengal was due to lack of interested workers and the fact that in the University of Dhaka there was no post-graduate classes in Botany until 1948, so that no research could be initiated in any branch of plant sciences. Immediately after partition of India in 1947 all the experienced botanists left the country when the post-graduate class was started with the recruitment of fresh graduates from the Calcutta University as teachers. They were also not interested in algal study and hence the research on this group had to wait for at least a decade, when Professor A.K.M. Nurul Islam started algal studies in the early fifties at the University of Dhaka. Nearly four decades of work resulted in significant contributions to the description of algae in Bangladesh."