SCIENTIFIC SUMMARY. 
445 
they contain a large tube, from which issue numerous branches in a digitate 
form, and all these parts present an appearance like that of tracheae. The 
name of false-trcichece which has been given to them, is perfectly justified, as 
they have no communication with the true tracheary apparatus, their prin- 
cipal function being to support the integuments of the palpi, whilst a true 
trachea ramifies in these organs. Parallel to the large trunk of the false- 
tracheae the labial nerve may be traced, of comparatively large size. It 
speedily divides into two parts, and emits a multitude of ramifications to 
the periphery and inner surface of the valves. Those nervous filaments 
which run to the periphery go to the numerous and greatly developed hairs 
with which the margin of the valve is furnished ; those which go to the 
inner surface on the contrary terminate at rudimentary hairs, reduced to a 
minute chitinous cylinder. 
On examining the nervous terminations which run to the marginal hairs, 
it will be found that a filament separates from the ganglionic inflation, and 
goes to the hair, as has been already described and figured by M. Jobert, 
but that it terminates in the interior of the hair at the point where the 
latter is joined to the integument by a membranous part. On the other 
hand, in the case of the terminations which go to the rudimentary hairs, 
the filament will be seen to traverse the little cylinder and project outside 
in the form of any fine and delicate rounded point. There are thus in the 
proboscides of the Diptera (Muscidae and Syrphidae) two kinds of nervous 
terminations — one set connected with well-developed hairs, which are no 
doubt tactile in function ; the other with rudimentary hairs of peculiar 
form, which are probably gustative. 
The Vertebrate Skeleton. — M. Sabatier has propounded certain views as to 
the nature of the Vertebrate Skeleton which are slightly at variance with 
generally-received opinions, although we fancy that something analogous 
has already been suggested more than once. M. Sabatier denies the exist- 
ence of the vertebral type, and regards the vertebra as nothing but the 
solidification of an intermuscular axis of connective tissue, the appendages 
of which are contingent and depend on the development and arrangement 
of the muscular system. Leaving out of consideration the cranium, the 
vertebral composition of which he regards as untenable in face of embryo- 
logical data, M. Sabatier remarks with regard to the rest of the vertebral 
column : — 
1. That the points of ossification are extremely variable as to number and 
position from one moment to another. 
2. That the typical parts of the vertebra are often deficient, as, for example, 
the centrum, which is sometimes only an appendage of the neurapophyses. 
3. That the parts of the vertebra are sometimes autogenous, sometimes 
heterogenous. 
4. That the caudal ribs or haemal arches of the tail in fishes completely 
change their signification, according as we have to do with osseous fishes, 
in which they are formed by the paraphyses, or with cartilaginous fishes, in 
which they represent true ribs. 
5. That the lateral apophyses of the body of the vertebra are multiplied 
where the muscular system is complicated. Thus the four lateral apophyses 
of the lumbar vertebrae of the dog and of the large carnivora originate from 
