AND THE DEVELOPMENT OF THE MYRIAPODA. 119 



At twenty-four hours (fig. 11.) after escaping from the amnion, the young animals 

 were lying together in a heap, but when disturbed, seemed to have acquired more 

 power of moving ; they remained quiet except when aroused, and had not yet taken 

 food. The only marked difference in their appearance, excepting that they had still 

 further increased in size, was in the nipple-shaped protuberances on the sixth and 

 seventh segments, the rudiments of future legs (h, c). These were now more distinct 

 and mammiform. Ten hours later in the day, they assumed still more the appearance 

 of nipples projecting from the under surface of the segments. When examined in 

 specimens that had been placed in spirit of wine, it became evident that these projec- 

 tions were occasioned by the development under the deciduous tegument of four new 

 but exceedingly minute legs, complete in all their parts, each covered by its proper 

 skin. The claws to the legs of the other segments were also more strongly marked. 

 The new segments {7-f) were now more developed, although still covered by the 

 common tegument, and, as in the preceding state, forming only one division of the 

 body, while a small space behind them {g) indicated the point from which other new 

 segments were to be produced. 



On the nineteenth day (fig. 12.) these animals had acquired a little darker colour, 

 but were still remaining quiet in their cells, and did not appear to have taken food. 

 The enlargement of the body had not extended to the prothorax, which did not in- 

 crease in size in proportion to the rest. The eye was more distinct, and the margins 

 of the segments were bordered with short red points. The double pairs of new legs 

 to the sixth and seventh segments, were now distinctly visible through the external 

 tegument, which had begun to be separated from the under surface of the old seg- 

 ments, to which, up to this period, it had closely adhered. The patch on the side of 

 the seventh segment had become darker, and the new segments were further 

 advanced. 



On the twentieth day (fig. 13.), although the animal continued almost motionless, 

 it had acquired much strength ; its limbs were much larger, and the claws at their 

 apex more distinct. In a specimen that had been hardened in spirit of wine, the 

 rudiments of the two double pairs of legs of the sixth and seventh segments (6, c), each 

 encased in its own proper skin, were seen coiled up, with all the articulations perfect, 

 while still further enlargement had taken place in the new segments. The common 

 tegument was extended over the new segments, as in the previous observations, and 

 the animals were still collected together among the burst envelopes of the eggs, and 

 the cast-off amnions, remaining, as it were, in a kind of pupa state. 



On the twenty-first day (fig. 14.) they were in the same condition, coiled up, per- 

 fectly quiescent, with their legs disposed side by side along the under surface of the 

 body, like the pupae of Lepidoptera. The new legs had now considerably increased 

 in size, as well as the whole animal, although it had not taken food. The animal 

 was still partially coiled up, but the skin that covered its body was greatly distended, 

 more especially along the ventral surface. It was less able to move than before, the 



