with Report on Experiments. 
371 
In this connection I regret that I did not execute and retain 
more figures of the intermediate stages 
witnessed in the embryos passing into 
larval state. After immersing the larvae in 
cold water, some of them soon became in- 
of larval growth, as 
the 
Fig. 8. — Embryo 
of Strontjyle from 
the Intestine of 
an Earth - worm. 
Length of an 
inch. Passing into 
the larval state. 
active and others were rendered motionless. 
I feared, indeed, that my investigations were 
already at an end, but the sequel proved 
otherwise. 
Further Experiments. — Seeing that no more 
structural changes were likely to be observed 
in the earth-worm larvae, it occurred to me to 
select a few of them and to place them on 
the moist fronds of ferns under a bell-jar. 
The pinnules of the ferns {^Aspleniiim bulbi- 
ferurn) being well covered with condensed 
vapour, I was able to place the young worms 
in dew drops, precisely similar to those that 
occur on the blades of grass in low-lying pas- 
tures. Accordingly, on the 27th of October, 
I deposited three or four specimens on the 
extremity of a marked frond. On the fol- 
lowing day, after the lapse of only twenty- 
two hours, I carefully detached a few of the 
terminal pinnules of the frond, and placing 
these under the one-inch Ross objecti"e-glass, 
I had the satisfaction of detecting one of the 
larvae in the act of cruising about very 
actively. The addition of a drop of water 
increased its activity, and it became extremely 
difficult to follow the little creature's eel-like 
movements. In size it had so much increased 
that it was now actually visible to the naked 
eye, measuring as much as of an inch from 
head to tail. 
The Larvse undergo Metamorphosis. — The 
simple experiment above detailed is sufficient 
to show that when once the larvae escape the 
body of the earth-worm, if the surrounding 
conditions are suitable, they will grow and 
develop with amazing rapidity. Their acti- 
vities are correspondingly increased. The conduct of the single 
experimental larva just referred to was watched from hour to 
hour, whilst one or two of the others were examined occa- 
sionally. It so happened that all the free larvae that specially 
engaged my attention turned out to be young males. Taking 
