420 
TRANSFORMATIONS OF INSECTS. 
On the tenth day the organ of circulation was noticed for the 
first time, and the great dorsal vessel was seen to pulsate. The 
head of the embryo had now begun to assume the peculiar 
corneous appearance common to the larvae of insects, and its 
body had much increased in size. On the eleventh day the 
head was more distinct, and the antennae appeared at its sides 
like short crescent-shaped clubs with their terminations directed 
forward. Above them the single ocelli were distinctly seen. On 
the morning of the seventeenth day Mr. Newport found all the 
embryos ready to leave their investing membrane. Some of them 
were already detached from the shell ; others were still connected 
with it. Their increase of bulk had been very great within the 
last few hours. The body was more straightened, the head less 
inflected under the thorax, and the eye was a dark-coloured spot 
above and behind the antennae. The greater length was produced 
by the growth of the posterior segments, more especially of those 
in the space before the last segment but one. This last segment 
but one is called the penultimate, and the space the antepenul- 
timate and germinal space, and the faint divisions of future 
segments were seen in it. The seven anterior or front segments 
were much enlarged. 
The third period of development was now entered by the 
animals divesting themselves of their membranous coverings (Fig. 
5). This was the first spontaneous act of the Myriapod , which 
curled itself up and appeared exhausted, and life was only proved 
to exist by occasional movements of the antennae. It possessed 
three pairs of legs, like the true insects, and yet no great physical 
change was observed to mark the line between the condition of 
an inert embryo and one capable of spontaneous movement. 
This gift characterises the beginning of the third period, and the 
vegetative life ends with it, for the Myriapods gradually acquire 
voluntary and instinctive faculties, both as regards the means of 
procuring nourishment and of preserving themselves from injury. 
In about an hour after leaving the membranes, the young Julus 
exhibited a marked change. Its head was elongated on the pro- 
thorax, the parts of the mouth were distinctly movable, and the 
eye, a single ocellus on each side of the head, acquired a darker 
colour. The whole body had increased a fourth in bulk. It now 
