With the aid of a high power microscope and a lapse-time camera, Dr. Arthur C. Pillsbury, a botanist of Berkeley, Calif., has been able to convince scientists that protoplasm actually passes from one cell to another in plant life – a fact that has been disputed in botanical circles.
In demonstrating this movement of protoplasm between plant cells. Dr. Pillsbury takes the blossom of a tradescantia, or spiderwort, and cuts off a stamen filament near the base of the pistil. He then mounts the specimen in a microscopic slide and carefully injects a brown fruit dye into the wall of an individual cell. Thus making the protoplasm visible, he is able to watch the dyed jellylike substance move.
Although each partition between the individual cells seems to wall the protoplasm from the next cell, a small amount filters through with each surge of the substance. Even high-powered microscopes do not show any visible opening between the cells but, according to Dr. Pillsbury, there must be minute openings which allow a small amount of the protoplasm through.
For example, explains Dr. Pillsbury, if you had along strong of macaroni that was soft and damp, and you tied a silk thread around every half-inch, you wold have a scale model of the stamen filaments. If each unit or cell was filled with living protoplasm, it would act in the same way even though no openings were visible.
The first picture in the accompanying sequence series shows the cells before the dye was injected. In the second picture, the brown fruit dye was injected in the left corner of the middle cell and was allowed to mix with the protoplasm for the next five minutes. Notice` how the jellylike substance has worked itself towards the right-hand corner. The third picture shows the protoplasm moving towards the end of the filament. While most of the substance has rebounded on the cell partition, a small amount is seen filtering into the third cell.
These photographs – taken for POPULAR SCIENCE by Dr. Pillsbury- were made in natural color under polarized light. Magnified 250 times their normal size, the tradscantia stamen cells were selected for demonstration purposes because of their clear cut definition and adaption for polarization.
