90 MESSRS. MURIE AND MIVART ON THE 
blances) in the nature of the hairy covering, the form of the body, and length of the 
limbs in genera of the group, the ear, as we have demonstrated, pertains to three types. 
If Lemur be taken as a standard, then Cheiromys much surpasses it in the relative size 
of the concha. Tarsius, Galago, and Microcebus diverge somewhat from Cheiromys, but 
agree pretty well together; they vary chiefly in the amount of excavation of the posterior 
helical pit. Mycticebus, Perodicticus, Loris, and Arctocebus are allied in the diminution 
of the pinna, in the depth of the posterior helical pit, and in the possession of the 
peculiar horizontal folds of the antihelix already adverted to. 
The precise advantages gained or the developmental relation and value of the above 
differences are not so very easily discerned. Reasons, no doubt, might be conjectured, 
such as adaptation to nocturnal habits, or derivation from an ancient type. Thus the 
large and wonderful moveable ears of the Galagos &c. probably assist them in their 
nightly predatory excursions, either guiding them to their prey, or warning them of 
hostile approach. On the other hand, the short-eared Mycticebine are not, as far as 
we know, one whit less nocturnal in their habits than are the Galaginine and 
Chiromyide, while their means of escape are much less effective. 
Man and the Gorilla! are characterized by having a pendulous ear-lobule ; while in 
the Chimpanzee and Orang it is sessile. In other quadrumana the lobule diminishes, 
or is so very small as to be considered absent. As we descend from Man and the 
Simiine, which possess a considerable incurved marginal helix, to the lower subfamilies 
of Monkeys, we find less inflexion of the helix, the upper or anterior portion only 
retaining a fold. In some Apes, e. g. Cynocephalus and Macacus, there is a faint 
depression or rudimentary posterior helical pit, while in others, as Hylobates and Ateles, 
no trace of this exists. Although the Primates have in many instances a transverse 
bifurcation of the antihelix, yet none have this forming a pouch. ‘The flat pinna is oval 
or roundish, the Cynopithecinw possessing a tendency to angularity. 
The Lemuroids, while presenting a similitude to Man and Apes in the outer organ of 
hearing, do not conform in every particular. So far as size and shape are concerned, 
Cynocephalus might represent Lemur, and Nyctipithecus be equivalent to Nycticebus ; but 
no Monkey whatsoever has the enlarged conch-like pinna matching that of Cheiromys 
and Galago. 
On the other hand, the ears of some lower animals approximate considerably to the 
Lemurine peculiarities. Thus the Carnivora, the Cheiroptera’, the Rodentia, nay, even 
the Marsupialia repeat characters manifested in them. For example, the Dog, Cat, 
and other well-known Carnivores have the posterior helical pit of remarkable size; and 
other genera among Bats have a most extensive pinna. The common Rat has the power 
‘ Owen, Trans. Zool. Soc. vol. v. p. 246. 
* Burmeister’s ‘ Tarsius,’ p. 8, where he remarks, “So merkwiirdig diese Bildungen auch erscheinen, so 
sind sie doch keineswegs ausschliessliche Eigenthimlichkeiten des Tarsiers, sondern finden sich in ihnlicher 
Weise theils bei den Fledermdusen, theils bei Nagern. Die innere Klappe hat z. B. auch Cavia.” 
