NO. 3662 PRIMATE BIOLOGY—NAPIER fa 
depend wholly on their own breeding stocks in the future as all 
Madagascan prosimians are rigorously protected. The value of 
prosimians as laboratory animals is largely unknown, but, generally 
speaking, their usefulness lies in the field of basic research. This is 
exemplified by the ongoing studies of Montagna and his colleagues 
on cutaneous anatomy and physiology. As substitutes for higher 
primates in the fields of cancer research, immunology, and pharma- 
ceutics, they leave much to be desired. 
NEw worLD MONKEYS.—The New World monkeys comprise two 
families, the Callitrichidae ! and the Cebidae. Marmosets (Callithriz) 
and tamarins (Saguinus) have enjoyed—if that is the right word—a 
high popularity during the last five years. Their principal advantage 
is their small size and the free availability, in particular, of Saguinus. 
The common marmoset (C. jacchus) is becoming increasingly rare 
according to certain authorities (Hill, in press). 
A discussion of the suitability, disease hazards, and basic biological 
data of marmosets and tamarins has been summarized by Deinhardt 
and Deinhardt (1966); breeding of marmosets in captivity has been 
discussed by Hampton et al. (1966). 
Although phylogenetically the most remote from man of all higher 
primates—and, therefore, of limited value in procedures that hinge on 
close genetic proximity to man—marmosets are most useful animals 
in certain specific research projects. In the study of viral hepatitis, 
for example, they appear superior to other nonhuman primates, always 
excepting the expensive chimpanzee (Deinhardt and Deinhardt, 1966). 
Among the Cebidae, the only species that merit consideration at 
the moment are the squirrel monkeys, the douroucoulis or night 
monkeys, and the capuchins. The shortness of this list reflects as 
much as anything the neglect of the New World genera by primate 
biologists. No doubt this neglect can be traced to the remoteness of 
this group from the story of human evolution, which in the past 
constituted the principal raison d’étre for studying primatology. 
Cebus, the capuchin, which is said to be resistant to tuberculosis, 
has been discussed by Stare et al. (1963), principally in relation to 
dietary factors in the etiology of atherosclerosis. Squirrel monkeys, 
which fulfill nearly all the criteria for the ideal laboratory animal 
except that of phyletic proximity, are widely used in neuroanatomical 
studies in arteriosclerosis research and in space physiology. One of the 
most surprising animals to emerge as a promising laboratory species 
1 The spelling of Callitrichidae is that originally used by Thomas (1903). The 
termination appears to be formed in accordance with Appendix D, Table 2, of 
the ‘International Code of Zoological Nomenclature’ (1964), and, therefore, 
there is no case for amending Thomas’ spelling. 
