can’t see the forest

Volvox is a genus of green algae (chlorophyta) found chiefly in puddles and ponds where rainwater is abundant. These algae form spectacular spherical colonies, composed of many individual algae, each of which has a light-sensitive eyespot and two flagella with which it can swim. The cells are connected to one another by strands of cytoplasm so that they can work together to propel the colony towards light.

These tiny swimming globes (only very large colonies exceed 1 mm in diameter) can sometimes be seen with the naked eye, but of course it’s under the microscope where things get interesting. The colonies have anteriors, where eyespots are more developed in the cells, and posteriors, in which reproductive cells are prominent.

In reproduction, daughter colonies are developed inside the parent colony through cell division. Eventually the parent disintegrates, setting its offspring free.

It is generally accepted that early land plants evolved from green algae. Many species of seaweed are classified as chlorophytes.

Wikipedia on Volvox
Wim van Egmond’s article in Microscopy UK
Mindscape Magazine on Volvox