130 
MR. NEWPORT ON THE ORGANS OF REPRODUCTION. 
ferred, from this fact, that this is the number of segments produced at each change 
in all the Chilognatha, or that the new segments are produced in a corresponding 
part of the body in the other divisions of this class, the Chilopoda. In these two 
orders the parts in which the new segments appear differ greatly, and most distinctly 
mark these two divisions of the Myriapoda. In the Chilognatha the segments are 
always produced as above stated, but in the Chilopoda, the proper Scolopendradae, 
according to Gervais*, the new parts are developed between each of the original 
segments. These are remarkable differences in the modes of growth of the two 
orders of this aberrant and most singular class. Although the new segments make 
their appearance at the same part of the body in all the Chilognatha, they differ in 
number in different animals of this group, and from the few observations I have yet 
made, I am inclined to believe that this difference is characteristic of different genera. 
Thus in lulus terrestris it is sextuple through the earlier periods of life, but in a 
well-defined genus, Blaniulus, nearly related to lulus, the number of segments at each 
reproduction appears to be quadruple, while in the young of another genus, which 
I believe to be Polydesmus, closely connected with the above, the number of seg- 
ments appears to be only twofold at each change. But in each of these instances 
the number of new segments is similar throughout the earlier changes of the animal. 
The development of legs takes place subsequently to that of new segments, which, 
when first produced, are always apodal, the legs being developed to the new segments 
at the next change of tegument. But as regards the number of legs produced, this is 
less regular than that of the segments. Thus in the hexapodous condition of the 
animal, legs are being produced to only two of the original apodal segments beneath 
the common tegument, while six new segments are in progress beyond them. When 
the skin is thrown off the legs are elongated, and the segments become more deve- 
loped. In the mean time new legs are being formed beneath the tegument for those 
new segments, while other new segments are being produced beyond the last of these 
organs of locomotion. In like manner the eyes make their appearance as one of the 
last commenced changes, while the antennse are the parts that earliest attain their full 
development. Such are the conclusions at which I have arrived in these investiga- 
tions, which I propose to continue at a future period. 
* Loc. cit. 
