40 THE DESCENT OF THE PRIMATES 



to each other, the point of meeting being thus 

 continually transported further backwards to- 

 wards yet older geological strata. Thirdly, the 

 necessity of inquiring into the early embryonic 

 details and placentation of every known genus 

 of Insectivora and of Primates is imposed upon 

 us, — the Insectivora being especially instructive 

 by the suggestive divergences which they offer in 

 their numerous types of placentation ; the Pri- 

 mates being more especially important with re- 

 gard to human development. 



Selenka has just made a commencement with 

 the ape-tribe, but nevertheless our acquaintance 

 with their development is as yet only very frag- 

 mentary. For a patient explorer there is yet a 

 very extensive field, and the monkeys of the New 

 World, as they are somewhat circumlocutionally 

 called, are certainly the first on our list of em- 

 bryological desiderata. I earnestly appeal to 

 your " scientists," — or, if as a European I might 

 be allowed to coin an Americanism, I would 

 rather say, to your " forshers," ^ ■ — to institute that 

 investigation without delay, even though it is not 

 in the United States that the material can be 

 obtained. However, the solidarity of the con- 



1 Perhaps the terra " researchers/' here and there used to 

 supplant the word "scientists," might be preferable. 



