1885.| Zoölogy. f 1000 
copula. This finally results in a sternebra which is intercostal, 
or intermediate between two successive pairs of ribs. A succes- 
sion of these intercostal copulæ between the true ribs form a 
sternum. Just as the true ribs are linked by copulæ that are in- 
termediate between two adjacent pairs, so are the costoids linked 
by intermediate copulæ, which may thus be distinguished as- 
intercostoidal paracopulæ and diacopulæ. These par- and dia- 
copulæ may develop between par- and diapophyses as well as- 
between par- and diacostoids. 
The views of M. Albrecht with regard to the evolution of what 
may be termed rib-junctions appear very plausible, but he coins 
some terrific polysyllables to explain their co-relations, as witness 
“ diparatetradiacopulaire.” This is worthy of organic chemistry, 
PRESENCE OF A TAIL IN THE HUMAN Empryo.—Does the human 
embryo ever present at the posterior extremity of its body any- 
thing which deserves the name of a fail? This question has 
given rise to a debate which has not failed to be a lively one be- 
cause necessary distinctions had not been made by the disputants,. 
and because they did not confine themselves to a strict definition 
of terms. 
_It is at the outset necessary to distinguish between teratologi- 
cal cases and normal embryological phenomena ; then it is neces- 
sary to agree as to the meaning of the word zai. Is this term 
applicable to any conical or cylindro-conical appendage of the 
posterior extremity of the back, formed of the tissues composing 
- it, or should we reserve it for an organ containing a prolongation 
of the vertebral column? It is this last definition which shou 
prevail; an appendage deprived of vertebrz is not a true tail in 
the anatomical sense of the word, but a simple caudal prolonga- 
ion 
In the teratological cases described by MM. L. Gerlach, Bar- 
tels and Ornstein, the appendage, sometimes filiform, sometimes 
voluminous, does not contain an incontestible vertebra, and the 
total number of these osseous pieces does not pass beyond the 
regular number of normal man. 
As regards young embryos it is impossible to decide the ques- 
tion if at the outset we do not determine the point where the 
caudal vertebra begin. Should we place the limit at the point 
where the tail leaves the body ? or should we be guided by the 
Position of the anus ? or better still should we call caudals all the 
vertebræ situated behind the sacrum? It is this last view which 
has prevailed in comparative anatomy, and we can say from this, 
point of view that adult man possesses a tail, since it presents 
four or five coccygeal vertebre situated behind the sacrum. The 
minimum, in this relation, is attained by the chimpanzee, which 
only two or three coccygeal vertebre. 
Should we wish to apply the name of tail to the portion of the 
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