LIFE'S SIMPLEST CHILDREN. 15 
ivcll, especially those which come close up to the 
shore. The small fry of the fish, the shrimp and the 
sand-hopper, the large jelly-fish, and the tiny trans- 
parent jelly-bells (see 3', Fig. 2 2), only to be seen by the 
keenest eye, as we dip out the water carefully in a 
glass. Surely these minute jelly-bells with their in- 
visible hanging threads must be some of the simplest 
and lowest forms of life. Not so, they are really 
very high up in the world compared with the forms 
we are seeking. 
If, indeed, we come out late some autumn evening 
when, after the sun has set and the sky is dark, the 
sea in some sheltered bay appears all covered with 
a sheet of light, we may see some of the beings 
of the lowest order of life with the naked eye ; for 
when we dip the liquid fire out in a glass vessel and 
examine it, we find in it hundreds and thousands of 
tiny bags of slime giving out the bright specks of 
light, and these little Noctilucae, or night-glows (2, 
Fig. 3), are, as we shall presently see, some of Life's 
simplest children, although not by any means the 
most simple of the order. 
No ; to begin at the very beginning and find the 
first known attempts at a living being, we must 
search long and carefully, not merely with our 
own eyes, but with the microscope. Then we may 
perhaps be fortunate enough to discover some won- 
drously small creature like that on the next page, 
which Professor Haeckel took out of the sunny blue 
waters of the Mediterranean, near Nice, in 1864. 
The largest specimen to be found will be smaller 
than the smallest pin's head, yet when seen under 
the microscope, this tiny speck appears with out- 
