164 A. A. W. HUBRECHT. 
And so both the facts and the reasoning, that is brought to 
bear upon them, convince us that there is an immense amount 
of probability, that already in the Eocene did those funda- 
mental ontogenic differences exist between the Primates as 
represented by Anaptomorphus and between the then existing 
Lemurs, which we now notice between Tarsius and the modern 
Lemurs, Ungulates, etc. 
I hope to have established in the preceding chapters my 
full right at exacting the application of all data we dispose 
of, both osteological and ontogenetical, to the settlement of 
questions of affinity between Mammalia. ‘That in very many 
cases, when groups that are exclusively fossil come under 
consideration, we will have to go by the osteological charac- 
ters only, is, of course, self-evident. But it does not diminish 
our conviction that if there, too, we could have had ontogene- 
tical evidence in addition to go by, our conclusions would be 
yet more emphatically trustworthy. 
In the case of the Primates it is all the more necessary to 
insist upon the ontogenetical characters being allowed to 
have their full weight for several reasons. Firstly, because 
a careful consideration of these characters makes it evident 
that man, the monkeys, and Tarsius are more primitive in 
the possession of their connective stalk than are the Lemu- 
roids with their free allantois, whatever may up to now have 
been said of the latter’s placentation being more primitive, a 
point which in Chapter V I have endeavoured to reduce to 
its true proportions. Secondly, because the osteological 
characters seem to be such as to induce most paleontologists 
to incline towards a perfectly gradual passage from the 
lemuroid to the anthropoidean type. The facts of ontogeny, 
however, should force them henceforth to look out for addi- 
tional characters by which Wortman’s Anthropoidea (already 
represented in the Hocene by Anaptomorphus, for which 
there is no reason at all to suppose that its blastocyst was 
not as similar to that of 'Tarsius as its dental and skeletal 
characters are) can yet additionally be distinguished in older 
formations from those forms which must have led up to the 
