560 
spot which exists on each of the preceding seg- 
ments to the seventh, marking the existence of 
the foramina repugnatoria. The germinal 
space (13-19) which existed in the preceding 
period and was then seen to be forming seg- 
ments, is now developed into six new apodal 
segments, from the 14th to the 19th inclusive, 
very much smaller and shorter than the rest, 
and a germinal s (A) is again forming be- 
tween the last of these and the penultimate 
segment of the body, which, as above stated, 
undergoes no marked change. The whole 
body is thus composed of twenty-one segments, 
including the head. The first twelve of these 
are now perfectly developed, as well as the last 
two, the intermediate ones being only in their 
preparatory states. The animals at this period 
ate voraciously some decayed leaves, rotten 
elm-bark, and raw potato. 
On the sixty-third day the Julus again 
changed its skin, and entered its sixth period 
of developement (fig. 326). It then had ac- 
quired twenty-seven segments to its body, 
which had greatly increased in size and was of 
a brown colour. It had now six distinct ocelli 
on each side of the head, and all the segments 
to the eighteenth inclusive were furnished with 
legs, of which it had now fifty-eight. Six addi- 
tional new segments had also been developed 
to its body. as in the preceding changes anterior 
to the penultimate segment (1 g h1i2345 6), 
and the germinal membrane behind them (2) 
was still in further course of developement, the 
penultimate segment (26) remaining always 
unchanged. The six i pats (28) from which 
legs had been developed had also the foramina 
repugnatoria marked with small spots, while 
the spots on the preceding six had become 
larger and darker in colour, and the animal 
might now be regarded as having acquired all 
the essential parts of its body, its subsequent 
growth doubtless being effected by a repetition 
of the same interesting phenomena. 
The observations of Monsieur Gervais rela- 
tive to the developement of the Scolopendroid 
Myriapoda, are the only ones on record with 
which we are acquainted ; and although these 
are extremely desultory and incomplete when 
compared with the masterly baw oe of Mr. 
Newport concerning the Julide, detailed above, 
they seem to shew that the changes under- 
gone by the Scolopendride, before they arrive 
at maturity, are scarcely less important than 
those we have been considering. M. Gervais 
studied more particularly the growth of Litho- 
bius, (fig. 309,) Scolopendre, which possess, 
when mature, fifteen pairs of feet, and also some 
individuals belonging to the genus Geophilus. 
A young Lithobius captured in the month of 
May was found as yet to possess only seven 
pairs of feet, ten segments in its body, two 
eyes on each side of its head, and but eight 
joints in its antenne Moreover, that only one 
segment, the anal, was deprived of feet, a cir- 
cumstance which at once forms a remarkable 
difference between the young Lithobii and the 
young Juli, which latter have several apodal 
segments at the posterior extremity of the 
body. By the eighth of June the same Litho- 
bius had fourteen joints in the antenns, and 
MYRIAPODA. 
-changed, another proof of the numero 
eight pairs of legs, tozether with eleven seg- 
ments to its body, including an apodal one for 
the anal segment. 
Another Lithobius of nearly the same age 
had already three eyes on each side, and a th 
only ten pairs of feet, of which the two post 
rior were still rudimentary and scarcely fe 
In another example, even when all if 
legs were present, the creature had not as | 
got its full complement of eyes, there being o1 
eight stemmata on each side, whilst in | 
adult animal the optic facets are numerous. 
It appears manifest, therefore, that the 
thobii, like the Juli, have the number of th 
segments increased as well as of their legs, a 
of the joints of their antenne; and, moreo 
that the number of their eyes increases ¥ 
their age, a remarkable fact, which M. Gers 
seems to have been the first to signalize. _ 
With respect to the manner in which — 
number of pairs of feet and of segments is | 
creased as the young Lithobius grows ok 
M. Gervais gives us the blow n 
ents 
i 
4 
a 
mation: “ Examined upon the ven 
of the body, the pedigerous 
adult Lithobius are found to arly 
size equal, but examined from above w 
they are, as it were, imbricated, some app 
larger and others smaller. The largest of 
pedigerous ents are the 1st, 3¢ 
7th, 8th, 10th, 12th, 13th, and 14th, the & 
last corresponding inferiorly to four hal 
ments, and consequently to four pairs of 
The 2d, 4th, 6th, 9th, and 11th, are | 
and feet already exist upon these sms 
ments even before the dorsal portion is d 
loped, so that what is permanently obsery 
in one of the posterior segments, which 
superiorly only one shield, obtains also : 
riod for two of the posterior 3, wi 
ave as yet but one dorsal plate, the sma 
the two dorsal plates not having as 
its appearance. This fact is remarkab 
we suppose the same phenomenon to be | 
stant with all the rings, it is easy to 
how at all ages there are fewer dorsal seg 
than there are pairs of feet.” : 
As relates to the Geophili, M. Gerva 
sures us the process is, in them, alto; 
1 
® ‘ 
c< 
rences met with in the physiology of the) 
genera of the class under consideratio 
not having completed his researches upo 
subject, the author of the memoir from 
we have quoted has not as yet inforr 
the result of his observations concernit 
Geophilide. 
Ss aoe a = : 
and physiology of these animals ry | 
The padeetiony refer to the followi: gw 
Newport, Philosophical Transactions 
Savi, Observazione per servire alla ia 
specie di Julus communissima. Bol , 1817. 
letin des Sciences Naturelles, Dec. - d 
scientificke di Paolo Savi, Pisa, 1828. De 
Abhandlungen zur — der In: >! 
» Revne zoologique, 
ivteniing 1839. T Ri pet G 
of the animal kingdom. 
ss 
a 
Ot 
