270 
RICHAED ASSHETON. 
There is, however, no necessity to believe that the real 
plicate type has been derived from the extreme cumulate 
type, as is suggested for Nycticebus, nor even of the extreme 
cumulate from the extreme plicate. A middle view may be 
safer, namely, to regard the condition of the carnivora as 
that from which the two extremes have evolved, and that the 
Lemurs by some such process as that suggested above have 
given rise to a secondary condition from the more cumulate 
type, and simulate roughly tlie plicate type. The earliest 
stages of a Lemur have not yet been described. If there is 
anything in the suggestion above, the earliest formed 
trophoblast of tlie Lemurs like Nycticebus ought to show 
“ cumulations.” 
I am entirely at one with the Professor when he recalls the 
great value of his discovery of the nature of the placenta of 
Tarsius, and not only the placenta, but the character of the 
blastocyst, the coelom, mesoderm, and allantois, which so 
closely resemble those of juan that they simply cannot be 
ignored if comparative anatomy is of any value at all as 
evidence of racial affinity. But I think it is not necessary to 
take so strong a view as Hubrecht does of the difference 
between Tarsius and the other Lemurs in these respects, and 
I have indicated a way in which the Lemurine may have 
been derived from the Tarsian condition. The condition 
seems to me to emphasise the affinity between Lemurs and 
Monkeys rather than to necessitate the complete separation 
of Tarsius from the Lemurs. So far as it goes the com- 
parison supports the view of Dr. Elliot Smith expressed in 
his letter in ‘Nature,’ vol. Ixxx, No. 2054. It is, however, a 
condition (juite sufficient to justify a grouping of the Lemurs 
into those with the pseudo-plicate “ Lemurine ” placenta and 
free allantois on the one hand and Tarsius with the cumulate 
placenta and early allantoic attachment on the other hand, 
the latter group being closer to the Monke}’s than the former, 
as, indeed, has been shown by other characters. 
