 |
 |
 |
Volvox. These photographs were taken with the Leitz Othomat camera which is attached to the Orthoplan microscope. Photograph (a) was taken with a X10 objective with a darkfield condenser in place. Photograph (b) is a medium power photograph of the edge of the coenobium showing individual cells and also newly forming daughter colonies . The last picture is a low power photograph taken in bright field showing the numerous daughter colonies that are forming. |
Volvox is very motile and usually occurring in large numbers and can be easily seen with the naked eye. Each single cell consists of a stigma, vacuoles and two flagella and looks very similar to a chlamydomonas cell. Each cell body on the surface of the sphere is separated by mucilage and protoplasmic strands.
 |
 |
 |
These three photographs show close ups of the cells that make up the wall of the hollow coenobium of the Volvox. The individual cells are connected to each other with protoplasmic strands, which can be double or single. In photograph (a) the arrows point to the red stigma that can be seen in each cell, these cells are phototactic and steer the alga towards or away from light. Photograph (b) shows the vacuoles that are found and also some double stranded protoplasmic connections. There are also some larger cells in the photograph that will form male gametes later on. Photograph (c ) shows the many rod like bacteria that were seen embedded within the mucilage that surround the Volvox.
 |
This photograph was taken with an X40 DIC objective and shows the sperm packets of the Volvox aureus. These sperm packets will eventually swim away and make a hole in a female colony, where they will break up into individuals and go on to fertilise the Volvox egg cells. The zygotes that form are thick walled and have a spiny coat. |