JANUARY 18, 1884.] 
be determined; but I believe it may be safely as- 
sumed that the synchronism is defined within com- 
paratively narrow limits; or, as previously expressed, 
**formations characterized by the same or very nearly 
related faunas in widely separated regions belong, in 
very moderate limits, to approximately the same 
actual age, and are to all intents and purposes syn- 
chronous or contemporaneous’”’ (Science, No. 41). 
Professor Geikie, who is quoted by your correspond- 
ent as supporting the orthodox doctrine of homo- 
taxis, or homotaxis in its broadest limits, judiciously 
refers to chronological divergences of only thousands 
of years, and not of millions (‘ Text-book of geology,’ 
pp. 617-619). ANGELO HEILPRIN. 
Academy of natural sciences, Philadelphia, 
Jan. 12, 1884. 
Free cervical ribs in the human subject. 
I send you a photograph of a notable and very in- 
teresting anatomical preparation well worthy of be- 
SCIENCE. 61 
in possessing two demifacets, instead of a full facet 
above and a demi-one below. The same subject was 
also badly put together in some other respects; e.g., 
one of the long thoracic ribs (I think the fifth) bifur- 
cated atthe sternalend. The specimens were handed 
to me by one of my pupils, Mr. Arthur J. Hall. The 
anomaly here figured, while not new, is so rare that 
I think I have seen but one illustration of it; namely, 
that given by Professor Owen in his ‘ Comparative 
anatomy and physiology of vertebrates.’ 
ELLIoTrT CovuEs. 
Smithsonian institution, Washington, 
Jan. 4, 1884. 
A possible solution of the standard time 
question. 
Although the adoption of five standards of time 
for the movement of railroad-trains in the United 
States has simplified the time question for the trav- 
Seventh cervical vertebra of the human subject, life size, seen from above; showing well-developed and 
freely articulated pair of cervical ribs. 
ing engraved and published in Science. It is the 
seventh cervical vertebra of the human subject, 
natural size, viewed from above, showing a pair of 
free cervical ribs. This demonstrates the fact that 
the so-called transverse process of a cervical vertebra 
consists of a diapophysis with a coalesced pleura- 
pophysis, the vertebrarterial foramen so characteristic 
of cervical vertebrae being an opening between these 
two apophyses. The photograph shows the prepara- 
tion so well that little description is required. The 
whole bone is seen to be a little distorted, and the two 
ribs are seen to be of different shape and size. The 
ribs are photographed a little apart from their respec- 
tive articulations, otherwise in situ. Each freely 
articulates, as usual with ribs, by its head with the 
body, and by its shoulder with the diapophysis, of 
the vertebra. The base of each diapophysis presents 
anteriorly a nick (deeper and more regular on the 
left than on the right side) which is a part of the 
vertebrarterial foramen proper, the rest of which is 
circumscribed by the rib itself; the whole space be- 
tween the vertebra and the neck of the rib being thus 
a large continuous opening of irregular contour. 
The lower border of the body of this vertebra pre- 
sents on each side a demifacet (not shown) for half 
of the head of the next (first dorsal) rib; so that the 
first dorsal vertebra must also have been anomalous 
elling public, I believe it is a matter of deep regrets 
that, since a change has been made, that change could 
not have been to a single standard instead of five, and 
that Greenwich time, as Mr. Schott very significantly 
queries in Science, No. 88. This is the more to be 
regretted, since the railroad companies have found it 
impracticable to make the changes on the proposed 
meridians, and since, as Mr. Schott rightly appre- 
hends, all ordinary business must always be con- 
ducted on local mean solar time. 
It appears to me that this whole question could be 
very simply and forever settled by the adoption of 
Greenwich time for the movement of all public con- 
veyances the world over, and the construction of time- 
pieces which would indicate at once both local mean 
solar time and Greenwich time. The only modifica- 
tion of the ordinary time-pieces needed, to enable 
them to indicate both times, is to provide them with 
two dials, one of which shall be movable about an 
axis, and capable of being set at any desired point. 
It is immaterial which dial is stationary: the same 
set of hands would sweep both dials, and indicate, of 
course, both times, at once. Thus provided, a person 
desiring to take the next train would be governed 
simply by the Greenwich dial. Furthermore, should 
his time-piece lose or gain, it would only be necessary 
to set it by either local mean solar time or by that of 
