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 Jidus 

 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 



