942 General Notes. 
Since the two last primary segments (Ursegmente), namely, the 
thoracic and abdominal, correspond to the two sections of the body 
of the perfect insect, we may regard the primary segmentation as 
an anticipation of the later or tertiary segmentation. Against such 
a view two important facts are opposed. First, it is not to be for- 
gotten that the primary segmentation does not conform to the tre- 
tiary, in that the head in the former does not constitute a primitive 
segment, but is divided into two sharply distinguished and hetero- 
geneous sectious, the primitive head segment (Urkopf ) and the gna- 
thophorous macrosomite. 
Secondly, against the hypothesis alluded to, the whole progress of 
segmentation is opposed. If the macrosomites of the primitive 
body were to persist, as such, together with their later subdivisions 
(microsomites), as stem-unities of a higher order, the above view 
would be to some extent justified. The relation is, however, alto- 
gether a different one, in that between the few and unequally seg- 
mented stage on the one hand, and the similarly segmented end- 
stage on the other, a many and unequally segmented middle stage 
is intercalated, which bears scarcely a recognizable trace of the ear- 
lier segmentation, and out of which the trimerism of the end-stage 
is developed anew by the fusion of certain groups of metameres. 
the tetramerism of the segmented primary stage may not be 
readily explained by the not very sharply expressed trimerism of 
the end-stage, its cause must, without doubt, be sought in certain 
definite conditions of segmentation of the ancestors of insects. 
But, as I would eSpecially point out, may the tetramerous germ- 
band stage here under consideration be compared with other adult 
similarly segmented arthropods without taking other matters into 
account, since, independently of the fact that our germ-band is not 
an independent (completed) living organism, there is wanting all 
support toa legitimate comparison of its macrosomites with other 
arthropods with few segments, such as the Nauplius, for example. 
ARCH ZOLOGY AND ANTHROPOLOGY.’ 
(Continued from page 856.) 
Dr. Brinton presented a human vertebra from Tampa’ Bay, 
Florida, found in the bog deposits of the quarternary geologic 
period. Its peculiarity was that the bony structure had p 
and been replaced by a deposit of iron called limonite, so that it was 
an iron instead of a bone vertebra. 
' This department is edited by Thomas Wilson, Esq., Smithsonian 
Institution, Washington, D. C. 
