116 MR. NEWPORT ON THE ORGANS OP REPRODUCTION, 



sides like short crescent-shaped clubs, with their terminations directed forwards. 

 Above them the single ocelli were distinctly seen. All the segments, posteriorly to 

 the third, exhibited the transverse line that indicated the division into double seg- 

 ments, and the posterior segments were much increased in size. 



On the sixteenth day none of the embryos had left the egg-shell, nor exhibited any 

 signs of motion. I now thought I could perceive some irregular movements in the 

 dorsal vessel through the skin and amnion. The whole body of the animal was 

 greatly enlarged, particularly in the posterior region, and more especially in that part 

 in which the new segments were making their appearance. The head had acquired 

 a slightly brownish colour, and the future eyes were more visible, being also slightly 

 tinged. The first period after the bursting of the shell was now soon to close, as the 

 amnion was greatly distended, and in a few of the specimens the funis was ruptured. 

 In the whole of them it had become so fragile as to be separated by the slightest 

 motion. 



On the morning of the seventeenth day (fig. 9.) all the embryos were ready to leave 

 the amnion. Some of them were already detached from the shell, others were still 

 connected to it. Their increase of bulk within the last few hours had been very great. 

 The body was now more straightened, the head less inflected under the thorax, and 

 the eye was a dark-coloured spot above and behind the antenna. The segments of 

 the body were divided by distinct reduplicatures of the proper tegument, and the legs, 

 folded side by side against the ventral surface, were much further extended beneath 

 the amnion (6. a). The transverse divisions of the first six segments strongly marked 

 the original segments ; and the amnion (c), now ready to burst, was tightly extended 

 over the dorsal surface, and by the elongation of the body was rendered more distinct 

 on the ventral. The great increase in the length of the animal was mainly occa- 

 sioned by the growth of the posterior segments, more especially those in the ante-pe- 

 nultimate space, — the proper germinal space or membrane (f), — the faint divisions 

 of which into new segments were now distinctly seen through the amnion. The 

 seven anterior segments, including the head, were greatly enlarged, and the hitherto 

 minute anal and penultimate segments (8. 9.), — in the first of which the remains of the 

 funis (d) forms a rudimentary anal spine, — had also been enlarged, and were now fast 

 acquiring the form they afterwards retain throughout the life of the animal. Some 

 of the specimens soon threw off their covering, and entered the third period of deve- 

 lopment. 



The animal was now greatly enlarged, and possessed three pairs of legs, but it still 

 lay with these newly developed limbs coiled up without voluntary motion. The am- 

 nion had been fissured at its anterior dorsal surface, and slipped off backwards from 

 the posterior segments, and lay at the anal extremity, while the animal itself with its 

 limbs coiled up appeared as if exhausted with these, its first, spontaneous efforts. 

 No other signs of animal existence were given than occasional slight movements of 

 the antennae. A second, a third, and then a fourth specimen gradually escaped from 



