The Age of Discovery, Chapter 5: A Gathering of Green Globes

Day 3: 0600 hours

At four bells I am pleased to report another uneventful night after holding station at a depth of three hundred centimeters.  Although no one else heard it, I was pulled twice from my slumber by a series of strange clicking sounds.  This morning when I queried Lyra about the sounds she theorized that they may be produced by yet another crustacean relative, noting that this behavior is similar to several tropical shrimp species.  However, the first light of day reveals no such animal near the Cyclops.

We enjoy a breakfast of robust Venezuelan-grown coffee, toast with jam, and a delicious salad made of the chloroplast gleaned from a damaged algal protist we collected the previous day.  Lyra informs us that the disc-like structures filling the chloroplast are composed largely of chlorophyll molecules.  They have a flavor akin to that of sweet peas.  With this culinary success we look forward to more micro world delicacies! 

While I enjoy the last sips of my second cup of coffee, the crew clears the table of dishes and utensils and unfurls the charts of the open water.  All are excited to set about planning the day’s explorations.

1030 hours...

Diving to a depth of 750cm we find ourselves adrift amongst a large population of beautiful green spheres.  With their gentle rotation and slow, almost dance-like movement through the open water, these organisms are enchanting to behold.  The scene before us could only be more mesmerizing were it accompanied by the accomplished strains of a Bach string concerto. 

Lyra, using her shipboard reference library, identifies these organisms as Volvox, first seen two hundred years ago by the pioneer of microscopy Antonie van Leeuwenhoek, and named a half-century later by Carl Linnaeus – Volvox globator.

“Skipper,” says Lyra with her usual enthusiasm, “let me go out there!  We need to learn how they rotate like that, and deduce the function of the smaller spheres inside.  Oh, please, Jonathan…”

“Capital idea, “ I respond – to Lyra’s surprise, I think.  “But if there are any signs of predators, you will return immediately.”

She nods and smiles as if she would be the last person in the entire micro verse to take any chances.

1045 hours…

Excerpt from Naturalist’s Log:
 What a thrill and honor to be the first person to ever swim through aquatic micro space!   The weight of the oxygen tank and helmet, though quite substantial aboard the Cyclops, are negated in the water, leaving me feeling quite unencumbered.  It took slightly longer to become accustomed to the Brownian Motion, a sensation that the water is vibrating over every part of me.  How envious Robert Brown would be!  He could never have known that humans would be experiencing pedesis for themselves a mere seventy-five years after his original observation of the phenomenon  – that of rapidly moving water molecules colliding with micro-sized pollen granules.
My first observation as I approached a Volvox is that it is not a single organism, but many living in concert.  The outer skin of the sphere is made up of thousands of small green cells, and each has a pair of whipping flagella, which flail outward from the sphere in a synchronized fashion.  The cells somehow coordinate the movement of their flagella.  Such activity must explain how the spherical colony spins and moves about. But how do the small single cells coordinate their efforts?
A closer look at the surface of the sphere reveals that the cells are actually interconnected by lines!  Might these lines transmit chemical signals between every cell in the colony, instructing them how to direct their flailing flagella?  I find myself wondering what environmental stimuli causes the colony to trigger such signals and redirect its course.  The greenish nature of the cells hints that, as with green plants, sunlight likely plays a role.
A most remarkable feature of these colonies lies inside them.  The translucent outer sphere surrounds a number of other smaller bundles of cells.  In some colonies these smaller spheres are quite compact, and in others they appear nearly identical, expect for size, to the large colonies.
A sudden surprise draws my attention! Overhead, one of the large spheres splits open, and the smaller daughter colonies inside escape, already rotating into the sunlight, leaving the now lifeless mother colony behind!  This must be how Volvox gives birth to new colonies.  Before I can swim away, one of the new daughter colonies passes dangerously close by.  The current from its flagellated outer cells sends me tumbling further away from the Cyclops.  I am caught in their eddy.  As I am pulled away by the current I reach out, grasping for anything.  Something touches my hand.  It is the tattered membrane of the mortally wounded mother colony.  I grab on to it and hold on for dear life as the daughter colonies move off.  I have been saved by their doomed mother.
                                                As entered by Lyra Saunders, MS Cyclops

Day 3: 1115 hours…

Never again! Lyra, by a stroke of uncanny luck, is now safely back aboard ship. Her encounter with the Volvox daughter colonies has forced me to make new rules for extra vehicular activities.  I informed our adventurous young naturalist that she will heretofore not be allowed on a diving assignment without escort.  As she turned away from me I am certain she was rolling her eyes.

We leave the Volvox group and enter a shadowy region.  Gyro theorizes that somewhere above us, on the pond’s surface, a lily pad or other floating object is preventing sunlight from penetrating down this far. 

I order the driving lamps illuminated – and the timing could not have been more fortuitous.  The electrical radiance of our Edison’s light reveals a huge translucent insect larva not three ship-lengths dead ahead!  Gyro reflexively spins the wheel and gives the monster a wide berth.  We spend several minutes observing the creature.  This phantom insect larva is virtually invisible, a factor that surely benefits the insect when it comes to snatching up smaller unwary larvae for a quick snack.  I cannot help but wonder if there are more of these invisible beasts lurking about.